This document provides an overview and technical training on an A1 vehicle. It covers the vehicle's main parameters, exterior and interior features, power train configuration, and how to disassemble main body components. It also discusses the diagnostic apparatus used for vehicle diagnosis, including an introduction to the diagnostic software and basic usage of the diagnostic tools. Several lessons cover the vehicle's engine machinery, manual and automatic transmissions, and chassis systems including steering, brakes, suspension, wheels, and tires. Class exercises are included throughout to help teach the material.

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Technical training of A1new vehicle

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Contents
Warning ..................................................................................................................................................................... 6
Lesson 1: Overview................................................................................................................................................... 7
1.1 Main parameters of A1 complete vehicle .............................................................................................. 8
1.1.1 A1 vehicle configuration ........................................................................................................... 9
1.2 Exterior, interior characteristics............................................................................................................11
1.2.1 Vehicle exterior.........................................................................................................................11
1.2.2 Vehicle interior..........................................................................................................................11
1.2.3 External rearview mirror.......................................................................................................... 12
1.2.4 Audio entertainment system .................................................................................................... 12
1.2.5 Instrument cluster with multi information display................................................................... 12
1.2.6 Sun roof ................................................................................................................................... 13
1.2.7 4/6 split rear seat...................................................................................................................... 13
1.2.8 Human multiple cup frame design........................................................................................... 13
1.2.9 Individualized glasses box and file folder................................................................................ 14
1.2.10 Deep freeze .............................................................................................................................. 14
1.2.11 Multifunctional leather steering wheel .................................................................................... 14
1.2.12 Side airbag optional for fashion version/4AT vehicle.............................................................. 15
1.3 Power train configuration characteristics............................................................................................. 15
1.4 Essentials for dissembling main body components ............................................................................. 16
1.4.1 Disassembly of front bumper................................................................................................... 16
1.4.2 Disassembly of front headlamp ............................................................................................... 16
1.4.3 Disassembly of door interior trim plate ................................................................................... 17
1.4.4 Disassembly of rear bumper .................................................................................................... 18
1.4.5 Disassembly of rear door trim plate......................................................................................... 18
1.4.6 Disassembly of right rear body interior trim plate ................................................................... 18
1.5 Class exercise I .................................................................................................................................... 20
Lesson 2: Diagnostic apparatus ............................................................................................................................... 21
2.1 System introduction .............................................................................................................................. 21
2.2 BDS diagnosis software start............................................................................................................... 21
2.3 Basic usage of diagnostic apparatus .................................................................................................... 22
2.3.1 Main interface.......................................................................................................................... 22
2.3.2 System management ................................................................................................................ 23
2.3.3 System information.................................................................................................................. 23

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2.3.4 VCI .......................................................................................................................................... 24
2.3.5 Recording................................................................................................................................. 25
2.3.6 Help.......................................................................................................................................... 27
2.3.7 Close button............................................................................................................................. 27
2.4 System diagnosis of diagnostic apparatus............................................................................................ 27
2.4.1 Diagnosis ................................................................................................................................. 27
2.4.2 Full vehicle scanning (reading network topology) .................................................................. 28
2.5 Class exercise II................................................................................................................................... 30
Lesson 3: Power train .............................................................................................................................................. 31
3.1 Engine machinery ................................................................................................................................ 31
3.1.1 Overview.................................................................................................................................. 31
3.1.2 Technical characteristics of engine machinery ........................................................................ 33
3.1.3 Essentials of dissembling mechanical part of engine............................................................... 40
3.2 Class exercise III.................................................................................................................................. 65
3.3 Engine management system................................................................................................................. 65
3.3.1 Overview.................................................................................................................................. 65
3.3.2 M7 system control strategy...................................................................................................... 67
3.3.3 Structure, principle and fault analysis of M7-Motronic system component ............................ 75
3.4 Class exercise IV ................................................................................................................................. 90
3.5 MF513 manual transmission................................................................................................................ 91
3.5.1 Overview.................................................................................................................................. 91
3.5.2 Disassembly of transmission assembly.................................................................................... 92
3.6 Class exercise V................................................................................................................................... 98
3.7 Auto transmission ................................................................................................................................ 99
3.7.1 Auto transmission overview .................................................................................................... 99
3.7.2 Transmission parameters........................................................................................................ 101
3.7.3 Mechanical structure.............................................................................................................. 102
3.7.4 Control system....................................................................................................................... 104
3.7.5 Conventional test ....................................................................................................................110
3.8 Class exercise VI ................................................................................................................................113
Lesson 4: Chassis....................................................................................................................................................114
4.1 Overview ............................................................................................................................................114
4.2 Steering system...................................................................................................................................114
4.3 Brake system.......................................................................................................................................115

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4.4 Suspension..........................................................................................................................................117
4.5 Wheel and tire.....................................................................................................................................118
4.6 Class exercise VII ...............................................................................................................................118
Lesson 5: Body electric ..........................................................................................................................................119
5.1 Overview ........................................................................................................................................... 120
5.1.1 Vehicle wiring harness arrangement ...................................................................................... 120
5.1.2 Vehicle power source ............................................................................................................. 120
5.2 Lighting control ................................................................................................................................. 122
5.2.1 Lighting switch ...................................................................................................................... 122
5.2.2 A1 vehicle lighting control .................................................................................................... 122
5.2.3 Headlamp height adjustment circuit ...................................................................................... 123
5.2.4 Fog lamp control.................................................................................................................... 124
5.2.5 Steering and hazard warning lamp control ............................................................................ 124
5.2.6 Indoor lamp control ............................................................................................................... 125
5.3 Electric rearview mirror..................................................................................................................... 126
5.4 Electric window................................................................................................................................. 127
5.4.1 Electric window system circuit.............................................................................................. 127
5.5 Wiper and water spraying .................................................................................................................. 128
5.6 Central door locking system and anti-theft system............................................................................ 129
5.6.1 Central door locking system.................................................................................................. 129
5.6.2 Intelligent anti-theft system................................................................................................... 130
5.6.3 New key match and add......................................................................................................... 130
5.7 Air conditioning system..................................................................................................................... 136
5.7.1 Air conditioning system description ...................................................................................... 136
5.7.2 Expansion valve..................................................................................................................... 136
5.7.3 Compressor ............................................................................................................................ 136
5.7.4 Air conditioning circuit.......................................................................................................... 137
5.7.5 Aid conditioning duct selection ............................................................................................. 138
5.7.6 Magnetic clutch of compressor.............................................................................................. 138
5.8 Airbag system.................................................................................................................................... 139
5.8.1 Airbag system description ..................................................................................................... 139
5.8.2 Airbag warning lamp ............................................................................................................. 141
5.8.3 Airbag system schematics...................................................................................................... 141
5.8.4 Clock spring........................................................................................................................... 141

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5.8.5 Disassembly of airbag in drive side ....................................................................................... 143
5.8.6 Disassembly of passenger airbag........................................................................................... 146
5.9 Audio system..................................................................................................................................... 148
5.9.1 System description................................................................................................................. 148
5.9.2 Audio horn............................................................................................................................. 149
5.10 Steering assistance system............................................................................................................. 150
5.10.1 Steering assistance system description .................................................................................. 150
5.10.2 Reverse assistance system principle ...................................................................................... 151
5.10.3 Self check on reverse assistance system................................................................................ 151
5.10.4 Radar detection scope ............................................................................................................ 152
5.11 Instrument.......................................................................................................................................... 153
5.11.1 Instrument description ........................................................................................................... 153
5.11.2 Instrument schematics............................................................................................................ 154
5.11.3 Dashboard disassembly.......................................................................................................... 154
5.12 Onboard network ........................................................................................................................... 155
5.12.1 Body network introduction .................................................................................................... 155
5.12.2 Onboard network ................................................................................................................... 155
5.13 Class exercise VIII......................................................................................................................... 157
Lesson 6: vehicle maintenance and PDI check...................................................................................................... 158
6.1 Vehicle maintenance .......................................................................................................................... 158
6.1.1 Lift and support...................................................................................................................... 158
6.1.2 Maintenance check table........................................................................................................ 158
6.1.3 Maintenance check essentials ................................................................................................ 161
6.2 New vehicle PDI................................................................................................................................ 165
6.3 PDI precautions ................................................................................................................................. 165
6.4 New vehicle PDI check ..................................................................................................................... 165
6.4.1 Pre-new vehicle preparation .................................................................................................. 165
6.4.2 Complete vehicle integrity check........................................................................................... 165
6.4.3 Engine compartment check.................................................................................................... 166
6.4.4 Chassis check......................................................................................................................... 166
6.4.5 Function check....................................................................................................................... 167
6.4.6 New vehicle road test............................................................................................................. 167
6.4.7 Check after return .................................................................................................................. 168
6.4.8 PDI check list......................................................................................................................... 168

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6.5 Class exercise IX ............................................................................................................................... 170
Lesson 7: Internal training ..................................................................................................................................... 171
7.1 Contents of internal training .............................................................................................................. 171
7.2 Training program formulation ........................................................................................................... 171
7.3 Training organization and preparation............................................................................................... 171
7.4 Training result testing and assessment............................................................................................... 172
7.5 Technical training skills ..................................................................................................................... 172
7.5.1 Language application skills.................................................................................................... 172
7.5.2 Time control........................................................................................................................... 173
7.5.3 Teaching mode control........................................................................................................... 173
7.6 Fault case preparation ........................................................................................................................ 173
7.6.1 Fault case collection channel ................................................................................................. 174
7.6.2 Fault case preparation ............................................................................................................ 174
7.6.3 Fault case usage ..................................................................................................................... 175
7.6.4 Fault case feedback and sharing ............................................................................................ 175
7.7 Technical support............................................................................................................................... 175
7.7.1 Remote technical support....................................................................................................... 175
7.7.2 Field technical support........................................................................................................... 175
7.7.3 Daily quality information feedback ....................................................................................... 177
7.7.4 Major accident information feedback .................................................................................... 179
7.8 Product recall..................................................................................................................................... 180
7.8.1 Channel and contents for product recall activity ................................................................... 180
7.8.2 Product recall procedure ........................................................................................................ 181
Case I: Real vehicle observation............................................................................................................................ 183

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Warning
To maintain vehicle without related maintenance training is dangerous. Risks arising out of injury, property loss and maintenance failure will increase. The vehicle maintenance procedure recommended in this manual is based on long-term summary and development of the skilled technician. The manual is helpful for technician without BAIC training; however, when the experienced technician with training conducts maintenance, there will be no risk. Whatever, we hope all users of this manual will at least know basic regulations. The "warning" and "notice" items in this manual are suitable for disposal of uncommon risks. During operation, such clauses shall be followed to avoid personal injury and vehicle damage or risk due to incorrect maintenance. Meanwhile, it shall be noted that such "warning" and "notice" items are not complete; we can't incorporate all risks arising out of violating these clauses. Operation regulations recommended and mentioned in this manual are valid methods for maintenance. Tools needed are specially designed for specific operation. When using operation regulations and tools not recommended by BAIC, the maintenance personnel shall safeguard their own safety and vehicle safety and avoid danger. Contents in this manual, including charts and technical provisions, are the latest information when copying this manual. BAIC retains rights to alter vehicle design and manual contents without additional notice. The company doesn't assume such obligations. Vehicle replacement component shall be original BAIC component or that meeting quality requirement of original plant components. If maintenance personnel uses component failing to meet quality requirement of original plant components, they shall secure personal and vehicle safety and avoid danger.
BAIC is free from any responsibilities arising out of problems when using this manual. Such problems may be caused by the following reasons (not limited to): e.g. personnel failing to receive adequate maintenance training, improper tool usage, replaced component failing to meet quality requirement of original plant components, failing to follow manual version update.

8. Lesson 1: Overview
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Lesson 1: Overview Product positioning: A1 is the quality elite car specially built for social elite after "1980s". Product feature: as the pioneer based on BAIC mini car platform, it adopts the most advanced international design idea and integrates proactive and enterprising BAIC spirit. The shape is bold and fashionable. Forceful front, deep front snipe grouped headlamp, dynamic and incisive and diving waistline, integrated glider wing Turn signal lamp and electric folding exterior rearview mirror with electric heating form unity of complete vehicle vision and function. Body dimension 3998mm×1720mm×1500mm, wheel base 2500mm, providing adequate seat space for drivers. Meanwhile, 6 in 1 all-round safety system and intensive safety protection for driver and passenger from inside to outside is a bright spot for A1. A1 is built according to five star safety standard; Pre-Safe active safety system has the standard configuration of ABS, EBD and brake priority system. They jointly constitute active safety configuration of A1. They used high strength anti-collision body, front, rear and four door anti-collision beam and equipped 6 airbags and auto fuel circuit shutoff better provide all-round safety production for car users. What's more, A1 also stands out in term of human design idea and technical equipment. Multifunctional steering wheel, only equipped CCS automatic cruise control system among the same level, intelligent video entertainment system compatible with iPod, 6.5 inch CD touch screen, GPS navigation and digital holographic reverse image and as more as 23 human storage spaces bring users with outstanding car usage experience.

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1.1 Main parameters of A1 complete vehicle
The complete vehicle dimension stands out among A0 vehicle or may even be compared to level B vehicle.
Model
BJ7130/BJ7150
Length
3998mm
Width
1720mm
Height
1500mm
Wheel base
2500mm
Front suspension
830mm
Rear suspension
668mm
Minimum ground clearance (full load)
≥114mm
Minimum turning diameter
≤11m
Approach angle (no load)
17°
Departure angle (no load)
25°
Engine type
4A90
4A91
Remark
Constant speed fuel consumption per one hundred kilometers
≤5.3L
≤5.5L
90Km/h Testing method specified by GB/T19233-2008
Composite fuel consumption per one hundred kilometers
≤7.2L
≤7.2L
Complete vehicle kerb mass
Total mass (Kg)
1090
Front axis load (Kg)
687
Rear axial load (kg)
403
Maximum designed total mass
Total mass (Kg)
1490
Front axis load (Kg)
790
Rear axial load (kg)
700

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1.1.1 A1 vehicle configuration
A1 product configuration table:
Style
1.3L
1.5L
Comfort version/5MT
Comfort version/4AT
Fashion version/5MT
Fashion version/4AT
Body type
HATCHBACK/5
HATCHBACK/5
HATCHBACK/5
HATCHBACK/5
Drive mode
Front engine front drive
Front engine front drive
Front engine front drive
Front engine front drive
Engine type
4A90
4A90
4A91
4A91
Engine displacement
1.299L
1.299L
1.499L
1.499L
Maximum engine power
73KW
73KW
83KW
83KW
Maximum engine torque
124N.m
124N.m
147N.m
147N.m
Emission standard
National IV
National IV
National IV
National IV
ABS+EBD




Collapsible steering column




Electronic accelerator




Main/auxiliary airbag




Driver seat safety belt prompt (symbol+voice)




Co-driver safety belt prompt (symbol + voice)
—
—


Safety belt height adjustment (B column)




Vehicle anti-theft and alarm system




Engine stop anti-theft




Kid lock/seat fastening frame




Brake system
Front disc and rear drum
Front disc and rear drum
Front disc and rear drum
Front disc and rear drum
Front fog lamp
—
—


Rear fog lamp




Speed induction lock




Drive lamp not close alarm




Electric sun roof
—
—


Integration headlamp




Steel hub+hub cap


—
—

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Style
1.3L
1.5L
Comfort version/5MT
Comfort version/4AT
Fashion version/5MT
Fashion version/4AT
Aluminum alloy hub
—
—


Spare tire




Dial instrument




Glasses box in the left top of main driver
—
—


Sun visor + Vanity mirror
Without vanity mirror
Without vanity mirror


4/6 Split folding rear seat




Adjustable angle of steering wheel




Electric heating defrosting for rear windshield




Electric exterior rearview mirror +folding +electric heating
Without folding and electric heating
Without folding and electric heating


Electric exterior rearview mirror with Turn signal lamp




Front electric window




Rear electric window
—
—


Deepfreeze




Auto wiper of front windshield
—
—


Auto lighting of headlamp
—
—


Electric digital display air conditioning




Adjustable height of headlamp beam




Intelligent rear wiper




Parking radar
—
—


One remote key and one common key




Quantity of audio loud speaker
4
4
6
6
CD+6.5 inch screen+GPS navigation
—
—


Single disc CD+radio+ USB+AUX


—
—
Three section multifunction steering disc
—
—


IPOD interface
—
—


Fashion version/4AT optional package: cruise control, side airbag, side air curtain, leather seat, leather steering

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wheel, reverse image, pre-tensioning force limited front safety belt, engine trim hood. The steel tire uses steel hub, wheel dimension 175/65R14. It is different from aluminum alloy hub wheel 85/55R15.
1.2 Exterior, interior characteristics
1.2.1 Vehicle exterior Vehicle front Vehicle rear BAIC A1 has forceful and shaped front; the used alien headlamp (snipe type) is very creative in shape; the design of corner with depression on both sides is full of strength, harmoniously matched with whole body; the overall shape has adequate sport sense! The taillamp is composed of two parts, body and tail gate; the high brake lamp is LED, high configuration fashion version/4AT vehicle license plate top decorated with silver color chrome plated trim bar.
1.2.2 Vehicle interior Interior A1 provides multifunctional steering wheel; the deep and shallow toned double color interior offers a warm feeling; the dashboard design is elegant and concise; meanwhile, the human design makes operation very convenient.

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1.2.3 External rearview mirror Reverse mirror The dazzling and smart rearview mirror with Turn signal lamp has heating and folding functions.
1.2.4 Audio entertainment system Navigation screen The touch screen is integrated with navigation and reverse image, making function of audio entertainment system more powerful.
1.2.5 Instrument cluster with multi information display Instrument cluster

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One classic big round instrument, one small one, matt dial and multi information display provide driver with necessary information.
1.2.6 Sun roof Sun roof Sun roof control switch The equipped sun roof greatly enhances the lighting and air exchange performance of the complete vehicle.
1.2.7 4/6 Split rear seat Rear seat 4/6 Split seat may enable whole or partial lying down of rear seat to meet different demands of customers.
1.2.8 Human multiple cup frame designCup frame The dashboard and four door storage boxes are equipped with cup frame, boasting of great practical value.

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1.2.9 Individualized glasses box and file folder Glasses box File folder The position of handle on top of cab is designed as the glasses box, which is very innovative.
1.2.10 Deep freeze Deepfreeze The glove box inside has the air port to open, which is connected to the evaporation box via air duct.
1.2.11 Multifunctional leather steering wheel Steering wheel The multifunctional leather steering wheel uses three section designs and is equipped with audio and constant speed cruise control switch.
Interior diagram of glove box

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1.2.12 Side airbag optional for fashion version/4AT vehicle Side airbag In case of serious collision on vehicle side, the side airbag will protect the side bosom of the passenger.
1.3 Power train configuration characteristics
Engine type
4A90
4A91
Fuel
Above No. 93 lead free gasoline
Above No. 93 lead free gasoline
Displacement (mL)
1299
1499
Ignition sequence
1—3—4—2
1—3—4—2
Idle speed
750±30r/min
750±30r/min
Cylinder quantity
Inline four cylinder
Inline four cylinder
Cylinder diameter (mm)
75
75
Piston stroke (mm)
73.5
84.8
Compression ratio
10.5:1
10.5:1
Fuel supply mode
Electric spraying
Electric spraying
Spark plug
K6RTM3
K6RTM3
Maximum power (kw/rpm)
73/6000
83/6000
Maximum Torque（N.m/rpm）
124/4000
147/4000
Side airbag

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Engine Auto transmission In terms of power, A1 is equipped with a new generation Mitsubishi 1.3L and 1.5L 4A9 series high performance full aluminum gasoline engine; among the same displacement, the overall engine is at a leading level; it uses MIVEC fuel efficient variable valve timing technology and thus realizes perfect balance between power and affordability. Besides 5 gear manual transmission, it is also equipped an automatic transmission with "economic", "snowfield", "sports" and "cruise" mode.
1.4 Essentials for dissembling main body components
1.4.1 Disassembly of front bumper Notice: firstly dissemble a screw hidden behind the license plate; after that carefully separate the front bumper; avoid damage on front bumper hanger.
1.4.2 Disassembly of front headlamp

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1.4.3 Disassembly of door interior trim plate After dissembling three screws, use the plastic crow plate to dissemble trim plate; to directly use screw driver or several other metal tools is prohibited.
Pay attention to hook!

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1.4.4 Disassembly of rear bumper Firstly dissemble rear taillamp of the body; after dissembling screw and fastener, hold the rear bumper and avoid dragging radar sensor wiring harness.
1.4.5 Disassembly of rear door trim plate Use the plastic crow plate to dissemble trim plate; the rear door lining is wholly fastened by fasteners.
1.4.6 Disassembly of right rear body interior trim plate

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Notice: firstly fold rear seat (it's possible to separately fold right rear), or else, it's impossible to dissemble right rear body interior trim plate; the trim plate is wholly connected via fasteners instead of anchor bolt.

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1.5 Class exercise I
1. Which descriptions on A1 body below are wrong : A. The door is five door hatchback type B. Total body length of BJ7130 is 50mm shorter than BJ7150（3998mm） C. Vehicle width (not including rearview mirror) 1720mm D. Vehicle height (no load) 1503mm 2. Which descriptions on A1 power train below are correct : A. Equipped engine power 83kw B. Maximum torque 147N.m C. Inline four cylinder engine D. The equipped auto transmission or manual transmission are both four gear transmission 3. Which descriptions on A1 lighting system below are correct: A. The headlamp is the overall design integrated with front fog lamp B. The high brake lamp is the diode type C. The split taillamp has the reverse lamp arranged in body D. Only the rearview mirror for fashion version has the Turn signal lamp 4. Which opinions on A1 optional package below are wrong: A. Only fashion version/4AT vehicle is equipped with optional package B. The optional package includes knee airbag C. The optional package includes seat side airbag D. The optional package includes reverse video system 5. Which opinions on A1 wheel below are wrong: A. Dimension of wheel equipped with aluminum alloy hub 185/55R15 B. Dimension of wheel equipped with steel hub 175/65R14 C. All spare tires use steel hub D. Equipped tires are bias tire 6. Which opinions on A1 passive safety device below are wrong: A. Main and auxiliary vehicle airbags use standard configuration B. Pre-tightening force limiting seat safety belt C. ABS anti-brake system+EBD electronic brake force distribution D. Collapsible steering column

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Lesson 2: Diagnostic apparatus
2.1 System introduction
With the increasing development of BAIC Group Co., Ltd., the current diagnosis system can't meet the needed demand. Thus, the brand-new after-sale diagnosis software system, BDS—BAIC Motor Diagnostic System is developed. BDS diagnosis system now has A1 vehicle for your operation. BDS vehicle recognition and full vehicle scanning can precisely position the specific module of a certain vehicle for diagnosis. In response to all modules of this vehicle, BDS provides fault code, real-time data display, forced output, module information, programming and encoding, etc; besides, BDS also provides vehicle fault data upload, save, analysis, new vehicle data update and several other functions. BAIC vehicle diagnosis includes the following components:
2.2 BDS diagnosis software start
1. BDS diagnosis system is the PC-based diagnosis system; it may directly install in PC via installation file; after installing BDS diagnosis software system, PC desktop will generate icon of BDS diagnosis software. 2. Double click BDS diagnosis software shortcut【】, BDS diagnosis system enter start state. The diagnostic apparatus desktop will pop out start interface of diagnosis software; see the figure below; the dynamic progress bar shows software start speed; the current version of diagnosis software is shown in the right bottom.

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3. After starting BDS diagnosis software system, it will enter main interface of diagnosis software.
2.3 Basic usage of diagnostic apparatus
2.3.1 Main interface
This menu function is the main interface menu to resume initial state of system; after clicking "main interface" to pop put conformation operation dialog box; click the "confirmation" button to resume the initial state of system.

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2.3.2 System management
Click system management to show dropdown menu shown in figure below.
2.3.3 System information
As shown in figure below, click system information and pop out system information display box. It displays related system information. 1. Software activation and upgrade (Currently no such demand, function reserved) click diagnosis software activation and upgrade to show activation, deactivation, upgrade, change password, shown in figure below.
Recognition option
Model: Engine: Transmission:
Program version Model data version CPU Clock Speed VDS disc remaining space Memory
System information
Parameter value
Comfirmation
Activation Deactivation Upgrade Change password
System information Diagnosis software activation and upgrade Set
System management

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2. Setting Click set to select language of diagnosis software system. Select the needed language, click "confirmation" button; restart BDS system and complete language function set (it currently supports Chinese and English).
2.3.4 VCI
Click VCI to show dropdown box, shown in figure below; click "Blue Tooth" or "USB" to select VCI connection mode. Click "USB"; the connection mode of BDS will automatically change as USB connection mode. Click " BlueTooth " to establish bluetooth connection mode Firstly connect USB port of VCI to PC and insert bluetooth device in the computer. Click "BlueTooth" to pop out Blue Tooth matching box; the system will automatically match bluetooth; if the following interface shows, BDS connection mode is successfully set as bluetooth.
Model: Engine: Transmission:
Recognition option

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After successful matching, plug out USB; connect VCI via bluetooth; under the empty environment, the maximum effective scope of bluetooth is 100m.
2.3.5 Recording
Click recording to pop out confirmation recording dialog box, shown in figure below. Click "recording" button to formally start recording. Click "yes" button to save the video recorded Import related information in the popped dialog box; click "confirmation" button to save.
Click stop and pop out save confirmation dialog box, shown in figure below.
Whether to save the video file?
Yes
No
Recognition option
Model: Engine: Transmission:

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Notice: the recording function is to record the whole operation process of the technician, which will help the technician to playback the operation process and analysis fault reason. Print Click print set to pop out print set box, shown in figure below. Select the corresponding printer and press "confirmation" button to finish set. In the printing following menu, select current screen and current diagnosis information to print. To select the current screen will print out the full screen. Select current diagnosis information to print out all diagnosis information, include that in the scroll bar not shown.
Dealer VIN code Brand Model Descriptions
The video file will be saved as
Confirmation
Cancel
Recognition option
Model: Engine: Transmission:

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2.3.6 Help
Click help and pop out BDS system operation manual.
2.3.7 Close button
Click "X" button on the right top of the interface to close diagnosis software system.
2.4 System diagnosis of diagnostic apparatus
In the vehicle recognition interface box, separately select correct vehicle, engine, transmission; the interface seen in figure. After selecting the corresponding vehicle, click the right bottom "begin button"; after manual recognition success, enter main interface.
2.4.1 Diagnosis
When finishing vehicle recognition, click "diagnosis" button From the figure, we may see that the diagnosis interface is composed of five components: "full vehicle scanning", "fault code", "real-time display", "forced output" and "module information"; the menu bottom shows network architecture; before "full vehicle scanning", the controller icon in the architecture shows grey, DTC data display “？”. The right bottom corner shows prompt information and DTC total. Lines for different communication protocol (including non-detection data line) will be displayed in different colors. Without "full vehicle scanning", the right bottom corner only has "begin" at the enabled state; other buttons are grey disabled state. Before scanning, the position of displaying "DTC quantity" will display “---”. Only after scanning, other buttons are enabled.

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2.4.2 Full vehicle scanning (reading network topology)
Select "full vehicle scanning"; click "begin" button in the right bottom corner and begin full vehicle scanning; during scanning, "begin" button is in depressed and disabled state. After scanning, for the controller with communication and no fault code, show green icon and DTC quantity as "0"; for the controller without communication, display grey and "X". For DTC with normal communication but fault code, show red icon and DTC quantity; during scanning, the position of displaying "DTC total quantity" will display “---”. Shown in figure. This "vehicle scanning" is the scanning on the vehicle network topology; through this scanning, it can be seen that the vehicle network topology is the bus type, of which, ECM, BCM, ABS and IC are in CAN network; the diagnostic apparatus can find out every module via CAN network; the airbag module communicates with the diagnostic apparatus via K_Lin network protocol. Through the color of the network topology module, we can basically judge basic module state, red-module has fault code; green-module normal; grey-module unable to communicate with the diagnostic apparatus. In the network topology structure interface, we can read fault code, delete fault code and execute network module communication list function. "To view fault code list" button; click "to view fault code list" in the right bottom interface and pop out fault code screen, shown in figure below:

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List" menu
Click "list" button; the interface switches from tree diagram to list, shown in figure below: Delete all fault codes" button
Click "delete all fault codes" button " to delete all fault codes in the module and re-scan full vehicle, shown in figure below: In the network topology interface, we can click all modules to enter the system corresponding to each module; in each system, we may use functions of fault code, real-time display (data stream reading), forced output, module information, data scanning, programming and code, which will facilitate our diagnosis on system elements. For the specific diagnosis, we may physically operate all systems. We take ABS system diagnosis as an example: In the network topology interface, click "ABS" to enter ABS system diagnosis interface:

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In this interface, we may conduct detailed operation on ABS system, which will help us to judge electric control issues in the system.
2.5 Class exercise II
1. Which opinion on BAIC vehicle diagnostic apparatus below are correct A. The diagnostic apparatus has to connect to the vehicle via dedicated line for vehicle B. The diagnostic apparatus may be directly connected to vehicle via bluetooth C. Bluetooth set is required before the diagnostic apparatus is connected to vehicle D. The diagnostic apparatus can only be connected to the vehicle via bluetooth 2. With respect to specific functions of the diagnostic apparatus, the technician A says: we can conduct system programming via diagnostic apparatus; technician B: we have to scan the vehicle network before entering the system, which opinion is correct: A. Technician A B. Technician B C. Both are wrong C. Both are correct 3. Which following functions can't be realized by "system management": A. Diagnostic apparatus version information may be read B. Diagnosis software activation and upgrade C. Capable of diagnostic apparatus language conversion, Chinese-English conversion D. Capable of diagnostic apparatus system set 4. Thinking: if the diagnostic apparatus can't conduct full vehicle scanning, what aspects shall we consider? _______________________________________________________________________________________

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Lesson 3: Power train
3.1 Engine machinery
3.1.1 Overview
This engine was firstly successfully developed by Mitsubishi in 2004. It was then launched in the developed countries out of Japan; through practice, its performance is widely recognized; presently, it was Mitsubishi's most advanced global engine with small displacement; for 4A91 engine, the displacement is 1.5L, maximum power 83KW, maximum torque 147N.m; these two parameters enable it as the global most advanced engine; the power per liter reaches 55KW, exceeding many 1.8L engine; besides, since this engine uses the full aluminum alloy, the weight reduces by 30 Kg; due to the adoption of timing chain, the air allocation is more precise. Meanwhile, the replacement free greatly reduces operation cost; according to the data just tested by the authorized national department, the fuel consumption per 100 Km is only 4.0L; this data has been lower than the fuel consumption than the domestic 1.0L vehicle; the fuel efficiency has topped the same displacement vehicle.
Engine appearance
Engine exterior
Resin intake manifold
Throttle body
Overhead ignition coil
Resin rocker chamber cover
Body front
Compressor of air-conditioning system
Water pump
Alternator
Engine oil filter element
Stainless steel exhaust pipe
Aluminum cylinder
Aluminum sprocket chamber cover

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1. Main technical parameters
Manufacturer
Model
Engine type
Displacement (mL)
Specification
BAIC Group
A1
4A90 4A91
1299/1499
DOHC, 16 valves
Specification:
Items
4A90
4A91
Displacement mL
1299
1499
Bore x stroke mm
75.0 × 75.4
75.0 × 84.8
Compression ratio
10.5:1
10.5:1
Combustion chamber
Single slope roof type
Single slope roof type
Cylinder quantity
4
4
Valve quantity
Air inlet
8
8
Emission
8
8
Valve timing
Intake valve open
BTDC 31°—ATDC1 9°
Intake valve close
ABDC 13°—ABDC63°
ABDC 21°—ABDC 71°
Exhaust valve open
BBDC 35°
BBDC 39°
Exhaust valve close
ATDC 5°
Rocker
Not equipped
Automatic clearance adjuster
Not equipped
Fuel injection system
Electronic control multi-point injection (MPI) system
Ignition system
Electronic control 4 coils
Alternator
Engine (equipped with inbuilt IC adjuster)
Starter
Direct drive
● Engine power curve

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● Engine number position Engine number position:
3.1.2 Technical characteristics of engine machinery
I. Engine composition The engine is composed of cylinder head cover, cylinder cover, cylinder, fuel bottom shell body, fuel bottom shell, etc. All system components constitute the whole 4A9 engine frame. The aluminum magnesium alloy cast cylinder may make engine lamp duty, improve radiation, acceleration performance and fuel efficiency. The result of 4A9 using cast aluminum cylinder is that the overall weight is even less than 80% of 1.3L 4G engine; 4A9 engine series uses full aluminum; besides, many components use resin; besides, it uses the hollow camshaft and the computer aided high strength compact design, which all make engine lamp duty and small; it's of great importance for small displacement engine so that the power of the engine may be fully displayed.

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Items
High performance low fuel consumption
Mini, lamp duty
Low emission
Low vibration, Low noise
Increased reliability
Aluminum cylinder
○
Efficient, lamp duty, compact cylinder head
○
○
○
Cylinder pad
○
Resin valve chamber cover
○
○
Direct drive valve
○
○
○
MIVCE
○
○
Low friction crankshaft connection mechanism
○
Timing chain drive camshaft
○
○
○
High integration aluminum timing cover
○
○
○
No circuit cooling system
○
Resin intake manifold
○
○
Arrangement of engine with rear exhaust
○
○
Stainless steel emission manifold
○
○
○
2. Inlet and outlet characteristics ● Resin inlet pipe The resin intake manifold may reduce weight, fuel consumption and cost. Lamp duty Small: the swirl type long pipe greatly shortens extension High performance: the long pipe enhances low and medium speed torque; the increased interior surface roughness greatly increases high speed power.

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● Resin valve chamber cover Reduce noise transmission Reduce vibration transmission Reduce weight Valve chamber cover ● Stainless steel exhaust pipe Lamp duty: produced with stainless steel, thin wall flange Increased performance: the long pipe with equal length greatly enhances medium speed torque Reduced heat capacity: the simple structure reduces heat loss
Swirl type long inlet pipe

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● Camshaft The camshaft is made of alloy cast iron; the structure uses shallow 5 bearing type to seek high rigidity, lamp weight and improve reliability Quenching treatment on camshaft tip increases abrasion resistor; to remove the tip of camshaft will make it lampweight The camshaft has the hexagon head for maintenance to increase maintenance convenience Outlet camshaft Inlet camshaft fuel passage Inlet camshaft signal wheel
Stainless steel pipe
Long inlet pipe with equal length
Stainless steel flange

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● Valve tappet To adjust valve clearance via replacement of valve tappet will reduce fault rate and noise. ● Timing chain transmission Timing chain Lubrication nozzle of chain

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In order to reduce production cost, many old typed engine uses timing belt; the belt and tensioner have to be replaced every several ten thousand Km. During normal usage, the lifetime of the timing chain may reach several hundred thousand Km; the engine shall not be rejected till rejection; the operation cost of the full life cycle may reduce by 5000~10000 RMB. ● Variable inlet MIVEC MIVEC technology used by 4A91 may optimize valve opening time phase and improve inlet volume. It may reduce fuel consumption and emission and improve performance under an extensive speed interval. The important factor to determine engine combustion pressure (to generate engine torque) is the inlet volume. Air inlet will change with many factors. The opening angle of the throttle valve (controlled by engine driver) is one of the important factors. Separate the factor controlled by the driver from other factors; when the engine operates in between 600RPM and 6000RPM, the valve timing is an important factor. The inlet volume may vary with engine speed. Thus, the correction valve timing shall not be adjusted under the scope of all engine speed. The variable valve timing is the mechanism to adjust valve timing to conform to different engine speed. 3. Characteristics of cylinder Lamp duty Aluminum die casting replacing iron casting Periphery component integration (air conditioning bracket, thermostat, water pump swirl chamber)
Low fuel consumption Cylinder water jacket changes into integral water jacket
High rigidity Enlarge the connection flange with the transmission (improve the connection rigidity of the power train) Analyze optimum design of the reinforced rib via CAD analysis
Cam sprocket
Camshaft angle sensor
VVT sprocket component
From the engine oil pump
Crankshaft angle sensor

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Engine composition diagram ● Fracture technology-based connecting rod Such new workmanship will enable natural and precise assembly of the detached connecting rod and connecting rod cover in the fracture surface without machining match surface; it thus realizes the purpose of reducing machining procedure and machining bed. Besides, the connecting rod section has higher matching precision. Besides, the uneven section contact surface may greatly improve contact surface and loading capacity of connecting rod. ● Design of crankshaft balance block In order to improve balance, for 1.5 engine, use 8 complete balance blocks; for 1.3 engine, use 4 balance blocks. 1.3 Engine crankshaft

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1.5 Engine crankshaft
3.1.3 Essentials of dissembling mechanical part of engine
1. Disassembly of engine, ignition system Disassembly precautions: camshaft sprocket bolt. ● Use the special tool, flywheel stopper to fasten flywheel. ● Clear threaded hole of crankshaft ● Clear crankshaft sprocket
Cylinder
Flywheel
Crankshaft pulley
Washer
Washing
Crankshaft pulley bolt
Engine oil
Crankshaft

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● Mount crankshaft sprocket ● Apply proper amount of engine oil to the thread. ● Clear seal-ring. ● Tighten crankshaft bolt to tightening torque 190 N·m. 2. Disassembly of air intake manifold Disassembly precaution: water pipe assembly gasket, thermostat, coolant temperature sensor, crankshaft position sensor and engine oil pressure switch. ● Water pipe assembly gasket. Mount water pipe assembly gasket in the cylinder; the washer projection part shall point to direction shown in figure. ● Thermostat Mount thermostat in the cylinder; the oscillating valve must be on top ● Coolant temperature sensor Remove the sealant possibly left in the engine coolant temperature sensor or cylinder head thread hole. Apply sealant to the thread part of the sensor (shown in figure). Sealant specification: LOCTITE 262 or equivalent class.
Projection part
Oscillating valve

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● Crankshaft position sensor Remove any sealant possibly left in angle sensor or cylinder mounting surface. As shown in the figure, apply the continuous sealant with diameter 1.7 ± 0.5 mm to the cylinder. Sealant specification: LOCTITE 5971 or equivalent class. Mount angle sensor in the cylinder; tighten 8.4 ± 0.6 N·m as per the specified torque. ● Engine oil pressure switch Remove the sealant possibly left in the engine oil pressure switch or cylinder threat hole. As per the diagram, apply sealant in the thread of the engine oil pressure switch. Sealant specification: LOCTITE 565 or equivalent class. Mount engine oil pressure switch in the cylinder and tighten torque till 10 ± 2 N·m.

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3. Disassembly of fuel bottom shell and timing chain shell Disassembly precaution: filter, fuel bottom shell, front oil seal, timing chain shell, valve cover. ● Engine oil filter During dissembling, use the filter wrench to dissemble filter.

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Mounting: Clean the mounting surface of the filter in the cylinder. Apply the engine oil to the engine oil filter gasket. Insert the engine oil filter till O ring gets contact with mounting surface. Use the filter wrench to turn 3/4 turn or torque 11 ± 1 N·m. ● Fuel bottom shell Disassembly: Dissemble fuel bottom shell bolt. Use the special tool in between the fuel bottom shell and cylinder, fuel bottom shell remover (MD998727). Or else, it may cause deformation of fuel bottom shell. Mounting: Remove sealant remaining in the cylinder, timing chain shell and fuel bottom shell. As shown in the diagram, apply Ф4.0 ± 0.5 mm continuous liquid sealant in position A of fuel bottom shell; Ф2.0 ± 0.5 mm continuous liquid sealant in position B. Notice: within 3 minutes of applying liquid sealant, complete mounting of fuel bottom shell. Sealant specification: LOCTITE 5971 or equivalent class: Tighten bolt till 7.6 ± 0.6 N·m. ● Front oil seal Use the special tool, crankshaft oil seal erector (MB990699) to mount front oil seal in the timing chain shell.

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● Timing chain shell Remove sealant remaining in the timing chain shell, cylinder and cylinder head. Mount special tool, oil seal conduit (MB991993) in the crankshaft. As shown in the diagram, apply Ф2.0 ± 0.5 mm continuous liquid sealant in position A of timing chain shell; Ф1.5 ± 0.5 mm continuous liquid sealant in position B. Within 3 minutes of applying liquid sealant, complete mounting of timing chain shell.
Oil seal
Timing chain cover

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Lesson 3: power train Mount timing chain shell Tighten timing chain shell to specified torque. Tightening torque: M6 8.4 ± 0.6 N·m M10 (support bracket) 39.5 ± 3.0 N·m M10 (pillar) 36 ± 3.6 N·m ● Valve cover Remove liquid sealant remaining in the valve cover, timing chain shell and cylinder head. As shown in figure, apply Ф4 mm continuous liquid sealant. According to the illustrated procedure, tighten the valve cover bolt to 9.0 ± 1.0 N·m.
Timing chain side

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4. Check on disassembly of timing chain Disassembly precaution: camshaft sprocket bolt, MIVEC sprocket bolt, timing chain, timing chain tensioner. ● Camshaft sprocket bolt Disassembly: hold the hexagon part of the camshaft with wrench and dissemble camshaft sprocket bolt. Assembly: hold the hexagon part of the camshaft with wrench and tighten camshaft sprocket bolt to torque: 88 ± 10 N·m.

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● MIVEC sprocket bolt Disassembly: hold the hexagon part of the camshaft with wrench and dissemble MIVEC sprocket bolt. Mounting: Apply the least amount of engine oil to the following points. Camshaft end Insertion hole of MIVEC sprocket (inner and outer surface) Thread and nut of MIVEC sprocket bolt Bearing surface of MIVEC sprocket bolt Mount MIVEC sprocket in the camshaft. Ensure MIVEC sprocket has been placed on the camshaft. Hold the hexagon part of the camshaft with wrench and check whether MIVEC sprocket turns. Hold the hexagon part of the camshaft with wrench and tighten camshaft sprocket bolt to torque: 64.5 ± 5.5 N·m ● Timing chain Mount timing chain; the blue timing chain fastener with similar distance shall be placed on top; the other blue timing chain fastener far from the two timing chain fastener shall correspond to the crankshaft side.
V.V.T. sprocket
V.V.T. sprocket bolt
Crankshaft

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Mount timing chain in the crankshaft sprocket; align mark of blue chain fastener and sprocket. Mount timing chain in the MIVEC sprocket; align mark of blue chain fastener and sprocket.
Timing mark
Timing chain fastener (blue)
Camshaft sprocket timing mark
V.V.T. sprocket timing mark
Timing mark
Timing chain fastener (blue)
Camshaft sprocket timing mark

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Mount timing chain in the camshaft sprocket; align mark of blue chain fastener and sprocket. At this time, turn one or two gears of MIVEC or camshaft sprocket to align mark of blue chain fastener and sprocket. Confirm three groups of timing marks are aligned. Mount chain guide rail and tensioner rod. ● Timing chain tensioner When pressing the plunger of the timing chain tensioner, as shown in figure, insert the pin to lock plunger. Mount timing chain tensioner in the cylinder. Disassemble pin from the tensioner. Tighten timing chain via tensioner rod. 5. Valve clearance adjustment ● Turn crankshaft clockwise till the mark in the camshaft sprocket and the cylinder head are aligned (put No.1 cylinder in the top dead centre of the compression stroke). Notice: the crankshaft shall turn clockwise
Timing mark

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● At this moment, measure clearance of the valve pointed by arrow. ● Use the thickness gauge to measure the clearance between camshaft base circle and valve tappet. Standard value (cold machine): Intake valve 0.22 ± 0.04 mm Exhaust valve 0.30 ± 0.04 mm ● If the measured value is inconsistent with standard value, record the measuring value. ● Turn the crankshaft clockwise till the timing mark in the camshaft chain goes to the illustrated position. At this moment, No.4 cylinder is at the top dead centre of the compression stroke.
Timing mark
Timing chain side
Emission
Air inlet

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● Measure the valve clearance shown by the arrow. ● If the measured value is inconsistent with standard value, record the measuring value. ● In case valve clearance exceeds the standard value, replace the valve tappet. Note: the valve tappet dimension has 31 levels; within the scope of 2.70-3.30mm, the interval is 0.02mm The rod marking and thickness are correlated as per the table below
Thickness mm
Identity mark
Thickness mm
Identity mark
Thickness mm
Identity mark
2.70
70
2.92
92
3.14
14
2.72
72
2.94
94
3.16
16
2.74
74
2.96
96
3.18
18
2.76
76
2.98
98
3.20
20
2.78
78
3.00
00
3.22
22
2.80
80
3.02
02
3.24
24
2.82
82
3.04
04
3.26
26
2.84
84
3.06
06
3.28
28
2.86
86
3.08
08
3.30
30
2.88
88
3.10
10
2.90
90
3.12
12
● As per the following mode, select valve tappet. Dissemble the valve tappet and measure its thickness. As per the method below, measure the correct thickness of the new valve tappet to reach the standard valve clearance. Thickness of new valve tappet Thickness of old valve tappet Measured valve clearance
Timing chain side
Emission
Air inlet
Wall thickness
Identity mark

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Equation: Intake valve A = B + (C - 0.22 mm) Exhaust valve A = B + (C - 0.30 mm) 6. Check on disassembly of camshaft Disassembly check priorities: camshaft front bearing cover, engine oil control valve, camshaft, valve tappet. ● Camshaft front bearing cover Disassembly: according to the illustrated number sequence, firstly, dissemble camshaft front bearing cover, and then, fastening bolt of each camshaft bearing cover.
Apply engine oil to all mobile component before installation

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Mounting: Mount each camshaft and determine the orientations of the positioning pin are in the illustrated diagram. No.2 and No.5 bearing cover of the inlet and outlet camshaft have same shape. Conduct correct mounting according to related mounting mark. Identity mark (stamped on No.2 and No.5 bearing cover) I: Inlet E: Emission According to the number sequence in figure, firstly tighten all camshaft bearing cover bolt and then the camshaft front bearing cover bolt.
Positioning pin

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● Engine oil control valve Mounting: O-ring shall not be recycled. Before mounting O ring, use the soft tape to wind the oil circuit of the engine oil control valve to avoid damage. The damaged O ring will cause oil leakage. Apply some engine oil in the O ring of the engine oil control valve. Mount engine oil control valve in the cylinder head. Tighten engine oil control valve till the specified torque: 7.6 ± 0.6 N·m Measure valve tappet, shown in the figure. If the measuring vale and the specified value are inconsistent, replace valve tappet as per the identity mark and table below. Each valve tappet has an identity mark corresponding to the illustrated position. The valve tappet dimension in 31 groups; within the scope of 2.70-3.30 mm, the interval is 0.02 mm
Identity mark Number
Wall thickness

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7. Disassembly of cylinder head and valve Disassembly check priorities: cylinder bolt, cylinder head. ● Cylinder head bolt Check all the re-used cylinder head bolt according to the procedure below. Measure the illustrated outer diameter (arrow "A") Measure the illustrated smaller outer diameter (arrow "B") When the difference of outer diameter (arrow "A" and "B") in two positions exceeds the standard value, replace cylinder head bolt Standard value: 0 - 0.15 mm Mount the cylinder head bolt and washer assembly in the cylinder head. According to the mounting sequence, tighten till the specified torque 24.5 ± 2 N·m. Ensure the bolt to reach the specified torque. As shown in figure, apply paint mark in the bolt cap and cylinder. Notice: If the bolt tightening is less than 180 degrees, the bolt will become loose; thus, the correct tightening shall be ensured.
Timing chain side
Paint mark
Paint mark

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If the bolt is over-tightened till more than184 degrees, fully loosen and then repeat the whole procedure. According to the correct sequence, tighten the cylinder head bolt till 180 to 184 degrees. 8. Check on assembly and disassembly on bolt piston and connecting rod Disassembly check priorities: piston ring, piston and connection bearing. ● Piston ring Gas ring Use the piston ring expander and install No.1 and No.2 piston ring. The identity mark of the piston ring shall be upward. Identity mark: No.1 ring: A1 No.2 ring: A2 The dimension mark of the piston ring is shown below:
Dimension
Dimension mark
Standard
No.1 ring
No mark
No.2 ring
No mark
0.25 mm extended dimension
25
Piston ring expander
Identity mark
Dimension mark

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Oil ring Install the main oil ring in the annular slot of the piston ring. And then, mount the scraper and lower scraper.
Dimension
Identity color
Standard
No mark
0.25mm extended dimension
Double blue Firstly, insert one end of the scraper in the piston slot; press the scraper in place with finger. Mount piston in the scraper and check whether it can flexibly move in both directions. The scraper position shall be in the illustrated position. The marked direction is consistent with the timing belt side: Apply engine oil to the piston perimeter, piston ring and oil ring. As shown in the diagram: arrange piston ring, oil ring opening (scraper and oil ring). Insert the piston and connecting rod assembly in the cylinder hole and ensure the forward mark of the piston top pointing towards the camshaft sprocket. Use the piston ring compression tool to fasten the piston ring; mount the piston and connecting rod assembly in the cylinder. Notice: don't violently knock piston and connecting rod assembly, or else, it may easily damage the piston ring.
Scraper
Scraper
Piston pin

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Connecting rod Connecting rod cover mounting According to the disassembly mark, mount the correct bearing cover in the corresponding connecting rod. Make sure the lateral clearance of the big connecting rod end conforming to the specified value. Standard value: 0.10 - 0.35 mm Limit value: 0.4 mm ● Connecting rod cover bolt mounting According to the procedure below, check all newly used connecting rod bolt. Separately measure outer diameter in 15mm and 30mm of the illustrated connecting rod bolt. When the difference of the outer diameter (measuring value at 15mm and 30 mm) exceeds the standard value, please replace the connecting rod bolt. Standard value: 0 - 0.1 mm

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Apply engine oil to the support surface of the thread and nut. Correctly install connecting rod cover and loosely mount bolt with finger. According to the procedure, tighten bolt to specified torque: 15 ± 2 N·m. As shown in figure, make pain mark in the bolt front. The beginning paint mark points to the tightening direction; make other paint mark in 90-94 degrees of the bolt front. Tightening bolt 90 to 94 degrees. The paint mark in the connecting rod shall be aligned with the paint mark in the bolt. Notice: if the bolt tightening is less than 90 degrees, the bolt will become loose. Ensure correct tightening. If the bolt is over tightened till more than 94 degrees, fully loosen the bolt and repeat the whole procedure. 9. Check on disassembly of crankshaft and cylinder
Paint mark
Paint mark

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Disassembly check priorities: crankshaft bearing, bearing bush cover bolt, cylinder. ● Crankshaft bearing Crankshaft bearing (upper) mounting According to the identity mark in the cylinder bottom and table below, select crankshaft bearing (upper).
Apply engine oil to all mobile component before installation
Timing chain side

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According to the illustrated identity color, differentiate the crankshaft bearing (upper).
Cylinder
Crankshaft bearing identity color
Identity mark
Journal diameter mm
1
50.000 - 50.005
Blue
2
50.005 - 50.010
Black
3
50.010 - 50.015
Red
4
50.015 - 50.020
Green Select and mount crankshaft bearing (upper).Please mount in the middle position. After mounting, measure the illustrated position, the error shall be within 0.5mm. Crankshaft bearing (lower) mounting According to the identity mark (as shown in figure) in the crankshaft rear flange and the table below, select crankshaft bearing (lower). Use the illustrated position identity color to differentiate the crankshaft bearing (lower).
Identity color
Slot
Production date

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Crankshaft
Crankshaft bearing identity color
Identity mark
Journal diameter mm
Y
46.019 - 46.024
Black
N
46.014 - 46.019
Red
W
46.009 - 46.014
Green
B
46.004 - 46.009
Purple Select and mount crankshaft bearing (lower). Please mount in the middle position. After mounting, measure the illustrated position, the error shall be within 0.5 mm. ● Crankshaft bearing cover/bolt mounting Mount bearing cover, subject to the illustrated position identity mark. Prior to mounting bearing bolt, confirm bolt length is below the limit value. If it is above the limit value, replace new bolts. Standard value: 75.3 mm
Identity color
Number

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Apply engine oil to the bolt thread and bearing surface. According to the illustrated sequence, tighten the bearing cover bolt to torque 35 ± 2 N·m. Use the special tool, angle gauge (MB991614); according to sequence, tighten bearing cover bolt to 60-64 degrees. Notice: if the bolt tightening is less than 60 degrees, the bolt will not be tight. Ensure tightening bolt. If the bolt tightening is more than 64 degrees, fully loosen the bolt and then repeat the whole tightening procedure.
Stem length

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3.2 Class exercise III
1. Which are the characteristics of the 4A91 engine machinery? A. Forgery connecting rod B. Timing chain C. Hydraulic tappet D. Stainless steel exhaust pipe 2. On the plastic bolt, which opinions below are correct: A. In order to obtain better tightening effect B. 4A91 cylinder head bolt uses plastic bolt C. The tightening method of the bolt is same as other bolt D. Replacement is required after disassembly 3. Sequence to mount big bolt? A. From both sides to middle B. From middle to both sides C. Tightening in single side sequence 4. Thinking and discussion: how to judge whether the timing chain is extended?
3.3 Engine management system
3.3.1 Overview
The engine management system is usually composed of sensor, micro processor (EMS) and actuator, which controls the aspirated air volume, injection volume and ignition lead angle during engine operation. In the electric control system of the engine, as the input part, the sensor is to measure various physical signal (temperature, pressure, etc) and convert it to the corresponding electric signal; EMS functions to receive the input signal by the sensor, compare sensor signal and conduct computation according to the set program; it generates the corresponding control signal and transmits it to the power drive circuit, which will drive the actuator to execute different actions. The engine will operated according to the set control strategy; meanwhile, EMS fault diagnosis system will monitor component or control function; once the fault is detected and confirmed, it saves fault code and reminds the driver of the present system fault via the fault indicator lamp; when the detected fault is cleared, the normal value will be resumed.
Engine
Sensor
Diagnosis
Diagnosis
Actuato

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Electric control system structure of M7 engine In M7 torque-centered engine management system, all interior and exterior engine demands are defined by engine torque or efficiency, as shown in figure. Various engine demands will be converted as control variable of torque or efficiency; such variables will be processed in the central torque demand coordinator module. M7 system will arrange the contradictory demands according to the priority sequence and execute the most important requirement; use the torque conversion module to get the needed injection time, ignition timing and several other engine control parameters. The execution of the control variable has no influence on other variables. It is the advantage of the torque-based main control system. When matching the engine, since the torque control system has independent variable, to match engine characteristics curve and pulse spectrogram is only based on engine data, which has no interference with other function and variable. Therefore, it avoids repeated calibration, simplifies matching process and reduces match cost. M7 torque-based system structure
Canister control valve
Inlet pressure temperature sensor
Throttle valve assembly
Fuel rail assembly
Camshaft position sensor
Ignition coil
Throttle valve position
Fuel injector
Stepper motor
Knock sensor
Water temperature sensor
Oxygen sensor (upstream)
Pressure regulation valve
Acceleration sensor (it may be used as ABS speed signal)
Oxygen sensor (downstream)
Fuel pump bracket
Fuel tank
Diagnosis interface
Fault indicator lamp
Anti theft
UAE8 component in EUII, EIII system
Increased component in EOBD
Efficiency i
Engine startup Catalytic heating Idle speed control
Efficiency
External torque requirement
Cruise control Speed limit Vehicle trends Drive performance
Internal torque requirement
Engine startup Idle speed control Engine speed restriction Engine protection
Torque
Torque
Torque demand coordinator
Coordinate demand between torque and efficiency
Realize ideal torque
Torque conversion
Injection time
Split cylinder fuel interruption
Ignition timing
Speed sensor

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3.3.2 M7 system control strategy
Motronic system adopts multiple point (sequence) injection control; it provides many control characteristics related to operator and vehicle or equipment; the system uses the combination mode of open loop and close loop (feedback) control and provides various control signals for engine operation. Main system functions include: ● The torque-based system structure uses the inlet pressure sensor/air flow sensor to determine the cylinder load under the static and dynamic state; it improves mixed gas control function λ close loop control ● Fuel cylinder sequence and injection ignition timing emission control function ● Catalytic converter heating/protection ● Canister control ● Idle speed control ● MIVEC control ● Function of anti-theft device ● Complete a series of OBD II function ● Management system for diagnosis function 1. Start control During startup, use the special calculation method to control air volume, fuel injection and ignition timing. In the start phase of this process, the air inside the intake manifold is static; the pressure inside the intake manifold shows the ambient atmospheric pressure. The throttle valve closes, the idle speed adjuster specifies a fixed parameter determined based on the startup temperature. In the similar process, the specific "injection timing" is designated as the initial injection pulse. The fuel injection volume varies with the engine temperature to promote the formation of oil film in the intake manifold and cylinder wall; therefore, when the engine reaches a certain speed, it's required to enrich mixture. Once the engine begins to operate, the system will immediately begin to reduce start enrichment till the finish of the starting condition (600…700min-1), completely cancel start enrichment. 2. Warm up and three way catalytic converter heating control Under the startup condition, the ignition angle will be constantly adjusted. It changes with engine temperature, inlet temperature and engine speed. After startup of engine under the low temperature, the cylinder charging volume, fuel injection and electronic ignition are adjusted to compensate requirement on higher engine torque; The process continues till rising to the proper temperature threshold value. In this phase, the rapid heating of the three way catalytic converter is the most important since the swift transition to the three way catalytic converter will greatly reduce exhaust emission. Under this condition, properly delay ignition lead angle and use exhaust to conduct "three-way catalytic converter heating"

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3. Idle speed control During idle speed, the engine doesn't provide torque to the flywheel. In order to ensure stable operation of the engine at very low idle speed, the close loop idle speed control system has to maintain the balance between the generated torque and engine "power consumption". During idle speed, it's required to generate a certain power to meet various load requirements. They include engine crankshaft, air distribution mechanism and auxiliary component, such as internal friction of the water pump. M7 system takes torque as the main control strategy; based on the close loop idle speed control, it determines the engine output torque needed by the idle speed under any operation conditions. The output torque will increase with reduced engine speed and decrease with increased engine speed. The system responds to the new "interference factor" via the required maximum torque, e.g. air conditioning compressor on/off or gear shift of auto transmission. Under the relatively low engine temperature, in order to compensate bigger internal friction loss and/or maintaining higher idle speed, it's required to increase torque. The sum of all these output torques will be transmitted to the torque coordinator; the torque coordinator is responsible for calculation and obtaining the charging condensation, mixture constituent and ignition timing. 4. Acceleration/deceleration and drag interruption control Some fuel injected in the intake manifold can't timely reach the cylinder to participate in the combustion. Conversely, it forms a layer of oil film in the intake manifold. According to the increased load and the extended injection duration, the fuel volume saved in the oil film will rapidly increase.
Water temperature sensor
Idle speed motor
Crankshaft position sensor
Fuel injector
Idle speed motor
Water temperature sensor

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When the throttle valve opening increases, some injected fuel will be absorbed by the oil film. Therefore, it's required to inject the corresponding make up fuel to provide compensation and avoid the mixture from getting thin during acceleration. Once the load coefficient reduces, the additional fuel contained in the fuel film of the intake manifold wall will release; during deceleration, it's required to reduce the corresponding injection duration. The drag or traction condition means the provision of engine power at the free wheel is negative. Under this condition, the engine friction and pump gas loss will make vehicle decelerate. When the engine is under drag or traction condition, the fuel will be interrupted to reduce fuel consumption and exhaust emission; what's more important, it's to protect three way catalytic converter. Once the speed reduces to the specific fuel restoration speed above the idle speed, the fuel system will re-supply oil. In fact, EMS program has the scope of restoring speed. Based on the dynamic change of engine temperature, engine speed, etc, they will make calculation and prevent the speed from reducing to the specified minimum threshold value. Once the injection system supplies oil again, the system will begin to use the primary injection pulse to supply make up fuel and re-establish oil film in the intake manifold wall. When the injection is restored, the torque-focused control system will make engine torque increase slow and steady (smooth transition). 5. λ close loop control The emission post treatment of the three way catalytic converter is the efficient method to reduce concentration of harmful substance in the exhaust. The three way catalytic converter may reduce hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxide（NOx）at 98% or more, which is converted as water (H20), carbon dioxide (C02) and nitrogen (N2). Such high efficiency can only be achieved in the very narrow scope when the engine over volume air coefficient=1; the purpose of λ close loop control is to ensure the mixture concentration in this scope. λ close loop control system only functions when it is equipped with oxygen sensor. The oxygen sensor monitors the oxygen content in the exhaust in the three way catalytic converter; the thin mixture （λ>1） generates approximately 100mV sensor voltage; the thick mixture （λ<1）generates approximately 900mV sensor voltage When=1, the sensor voltage has a step. λ close loop control responds to the input signal (λ>1=mixture too thin, λ<1=mixture too dense) and modifies the control variable; the generated correction factor is used as the multiplier to correct injection duration. Although EMS controls the air fuel ratio of the mixture by calculating the optimum injection pulse width through complex method, the engine operation state is very complex; sometimes, it can't make the air fuel ratio of the mixture optimum. For example: in case of inlet passage leakage, fuel injector blockage, etc, the engine management system uses the oxygen sensor to correct the fuel injection to more precisely control air fuel ratio.
The oxygen sensor judges the air fuel ratio of the mixture by comparing the difference of oxygen condensation in the exhaust and the ambient air. If the oxygen content in the exhaust is very low, the mixture
Crankshaft position sensor
MAP sensor
Throttle valve position sensor
Fuel injector

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is dense; or else, it is very thin. The oxygen sensor generates direct current voltage signal, with signal voltage in between 0-1V; if the signal approaches 0V, it means the mixture is thin; when the signal approaches 1V, it means the mixture is dense. ● Close loop control When the oxygen sensor reaches the normal operation temperature, after normal operation, EMS may enter close loop fuel injection control state (shown in the following figure). EMS firstly calculates fuel pulse width and makes correction according to oxygen sensor feedback. Operation condition for closed loop mode: Engine temperature higher than set temperature Oxygen sensor at operation temperature When the timing delay finishes, the timing is variable; it is determined by the connection temperature of the ignition switch. If the oxygen sensor shows the feedback air fuel ratio is thick, EMS will reduce injection pulse width; or else, EMS will increase the close loop control of the fuel pulse width to make the theoretical air fuel ratio "sway" within the scope of 14.7; the oxygen sensor signal also "sway" around 0.45V. According to oxygen sensor output voltage: EMS adjusts fuel injection pulse width. This is how the air fuel ratio feedback controls the air fuel ratio at 14.7:1. ● Open loop control Although close loop control may achieve better effect, under certain circumstance, it can't enter close loop control state, the engine is in open loop state. These conditions include: Engine cold startup Large engine load Deceleration or speed limit Protection mode of three way catalytic converter After engine cold startup, the oxygen sensor fails to reach the normal operation temperature and can't give normal signal, at this moment, EMS will wait for normal signal of oxygen sensor. When the engine operates under big load, EMS intentionally enriches the mixture to get bigger power; at this moment, the oxygen sensor signal is neglected When EMS detects that the emission temperature is too high and may possibly damage the three way catalytic converter, it will give up the close loop control to reduce emission temperature. 6. Evaporation emission control
Due to external radiation heat and oil return heat transmission, the fuel inside the fuel tank is heated and form
Oxygen sensor, rear
Oxygen sensor, front

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fuel steam. Due to restriction by the evaporation emission rule, the steam with large volume of HC is not allowed to drain in the air. The fuel steam in the system will be connected in the active canister via the pipeline. In order to the make the active carbon absorb new fuel steam, the fuel steam absorbed in the canister shall be diverted to the engine for combustion via pipeline. The engine steam flow is realized via the canister solenoid valves controlled by EMS. This control only works under the close loop condition of λ close loop control system. When the hydrocarbon (HC) in gasoline form exposed in the air will evaporate sometimes; it may evaporate even in the fuel box. Whether the vehicle drives or not, the evaporation will occur. EVAP system functions to control steam emission caused by the steam evaporation. EVAP system collects and saves the fuel steam for combustion and prevents them from leaking in the air. During engine operation, under vacuum function of the engine, the fuel steam is absorbed in the engine for combustion. EVAP system has to collect and control steam in the fuel box. For the fuel evaporation exhaust (EVAP) control system operation, when engine stops and the pressure increases, the evaporation gas in the fuel tank flows out and is absorbed by the canister. During engine operation, the steam absorbed by the canister and air diverted from the canister orifice will jointly flow through solenoid valves, which then supplies to the engine according to the operation condition of the engine. If the fuel tank pressure reduces, the air will get via the canister orifice through overturn safety valve. If the canister orifice is blocked, the filler cap negative pressure valve opens, the air is diverted in the fuel tank to prevent the vacuum in the fuel tank from getting bigger and thus increase fuel tank load. In case of fault on the overturn safety valve, the filler cap position pressure valve opens and the evaporation gas is drained in the air to prevent fuel tank pressure from getting bigger and thus increase fuel tank load. The control principle of EVAP system is shown in the figure below. ● System element Canister solenoid valves The canister solenoid valves is composed of the spring, coil and plunger. According to the canister solenoid valves control signal sent by EMS (load signal), open and close solenoid valves passage and control the evaporation steam volume diverted to the intake manifold according to the engine operation condition. Signal sent by EMS will energize and magnitify coil and pull the plunger. When the plunger is pulled, the passage between the valve port opens; according to the vacuum of the intake manifold, the evaporation steam is diverted to the inlet system. Through the duty cycle control signal, EMS will control solenoid valves opening and the washing flow of the canister. Safety valve The overturn safety valve will prevent the fuel from entering the evaporation gas passage during overturn or rapid cornering. The inbuilt check valve (bi-directional) is placed inside the fuel pump assembly and maintains constant pressure in the fuel box.
Safety valve
Canister
Solenoid valves

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Canister The canister contains the active carbon temporarily absorbing steam. During the process of washing the solenoid valves, the air enters the canister from the aeration, wrap the active carbon and drain the steam. ● System control According to the engine operation condition, the canister solenoid valves will supply proper amount of steam to the power room to ensure drive performance and prevent steam from releasing in the air. EMS determines the engine operation condition via the signal from the input device and drives to wash the solenoid valves. 7. MIVEC control Continuous variable valve timing of the variable valve timing mechanism (open and close). The majority of delay time is BTDC-19˚（open）and ABDC63˚（close）; the majority of lead time is BTDC31˚（open）and ABDC13˚（close） In other words, the intake valve timing will change the angle of crankshaft relative to the camshaft 50˚. The important factor to determine engine combustion pressure (to generate engine torque) is the inlet volume. Air inlet will change with many factors. The opening angle of the throttle valve (controlled by engine driver) is one of the important factors. Separate the factor controlled by the driver from other factors; when the engine operates in between 600RPM and 6000RPM, the valve timing is an important factor. The inlet volume may vary with engine speed. Since the correction valve timing can't be adjusted within all the engine speed scope. The variable valve timing is the mechanism to adjust valve timing to conform to different engine speed. The valve timing characteristics determine engine characteristics. Use the variable valve timing mechanism; the engine may generate adequate torque at the full speed scope of the engine. ● System element The variable valve timing mechanism includes variable valve timing actuator, OCV, CKP sensor, CMP sensor and EMS. ● System introduction
Interface A
Interface D
Interface B
Interface C
Special tool
Exhaust valve stroke curve
Valve stroke
(Phase angle) 50°
Intake valve stroke curve (maximum lag angle)
At maximum lead angle
Overlap part
Curve angle

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Based on the following sensor signal, EMS controls valve timing to adapt to different engine conditions. In order to realize the expected valve timing, EMS drives OCV to changeover the hydraulic circuit from and to the variable valve timing actuator. ECT CKP CMP TP MAP Via the variable hydraulic circuit, the variable valve timing actuator determines the relative position of the camshaft and camshaft gear; under different driving condition, it obtains the most suitable valve timing. ● Lead and delay Valve timing lead When OCV servo valve receives EMS output signal and moves left, the engine flows from the engine oil pump to the valve timing lead channel and generates pressure, besides it will expand to the valve timing lead chamber. Thus, the rotor close to crankshaft will rotate along the lead direction of the valve timing. Since the sprocket is driven by the crankshaft timing chain, the position of the camshaft to the crankshaft will lead. In the chart above, the variable valve timing actuator rotates clockwise. When the valve timing lead chamber opens, the rotor is forced to rotate clockwise. Relative leading of rotor position Valve timing delay
Phase angle 25°
Lead angle chamber
Lag angle chamber
At the maximum lag angle
At maximum lead angle
Middle position
Fixation pin
Hydraulic circuit for lag angle
System for lag angle
System for lead angle
Hydraulic circuit for lead angle
Hydraulic pump
Shell
Pin
Cover
Sprocket
Rotor
Seal

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When the OCV servo valve receives right move of EMS output signal, the engine oil flows from the engine oil pump to the valve timing lag channel and generates pressure; besides, it expands to the valve timing delay chamber. Therefore, the rotor close to the crankshaft rotates along the valve timing lag direction. Since the sprocket is driven by the crankshaft timing chain, the position of the camshaft relative to the crankshaft will lag. In the chart above, the variable valve timing actuator rotates counterclockwise. When the valve timing delay chamber opens, the rotor is forced to rotate counterclockwise. The rotor position relatively lags. With respect to the variable valve timing control operation, according to the operation condition of the engine, EMS divides the drive scope of the engine oil control valve OCV into four modes. The drive current of OCV is calculated based on the target current under each mode. Maximum camshaft lag mode In case of any of the following conditions, it will execute the maximum camshaft lag mode: Startup Idle speed after completing clean mode Save fault code with the following input/output equipment: ECT,CKP,CMP,TP,MAF,OCV ● System diagnosis According to the calculation value corresponding to the monitor value, drive OCV; the feedback mode obtains the optimum valve timing to conform to engine condition. According to the engine operation state, the target current value is 600mA, in between 100mA (maximum lag) and 950mA (maximum lead). In order to obtain the target lead or lag volume, the target current value uses the study current value under the locking mode as the reference value. The target valve timing is calculated based on the engine speed and inlet efficiency. The actual valve timing is calculated based on the sum of the measured maximum camshaft lag study valve of CMP and CKP. 8. Knock control Based on the characteristic vibration generated by the knock sensor mounted on the proper engine position, the system converts the detected vibration into the electronic signal to facilitate input in EMS and processing. EMS uses the special algorithm and detects whether there is knock during the combustion cycle of each cylinder. Once the knock is detected, it will trigger close loop control. When the knock hazard is eliminated, the affected cylinder ignition gradually leads to the set ignition lead angle. 9. Fan control ● Control strategy for cooling fan Adopt dual speed fan, controlled by the dual relay; during air conditioning, operate at low speed; operate at high speed during high temperature.

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3.3.3 Structure, principle and fault analysis of M7-Motronic system component
The engine EMS receives many input signals of the sensors and outputs it to control multiple actuators. Control signal: ME788 system input/output signal. EMS main sensor input signal in ME788 system includes: ● Inlet pressure signal ● Accelerator pedal signal ● Inlet temperature signal ● Coolant temperature signal ● Engine speed signal ● Phase signal ● Knock sensor signal ● Oxygen sensor signal The above information enters EMS; after processing, it generates the needed actuator control signal; such signals will be amplified in the output drive circuit and transmits to the corresponding actuator, such control signals include: ● Electronic throttle valve opening ● Injection timing and injection duration. ● Fuel pump relay ● Canister control valve opening ● Ignition coil close angle and ignition lead angle 1. Input signal device Inlet pressure temperature sensor
Power source for ignition switch
Earthing wire
Normal power
Normal power
Fan relay1
Fan relay2
Fan of water tank