The document provides an overview of the key components and systems of an automobile, including: 1. The chassis, engine, clutch, gearbox, propeller shaft, differential assembly, half shafts, suspension system, steering system, braking system, cooling system, lubricating system, and electrical system. 2. Descriptions of each system and their basic functions in propelling and operating the vehicle. 3. Classifications and examples of different types of components within each system, such as types of transmissions, clutches, suspensions, and more.

1. by Manoj Kumar tj
Mandovi ,motors
Mangalore

2. (1) Chassis
(2) Engine/power plant
(3) Clutch
(4) Gear box
(5) Propeller shaft(rear wheel) & driving shaft(front wheel)
(6) Differential assembly
(7) Half shaft
(8) Suspension system
(9) Steering system
(10) Braking system
(11) Cooling system
(12) Lubricating system
(13) Electrical system (starting & charging )
Basic Engine terminology

3.  Definition
 The term automobile refers to self propelled
vehicle /vehicle which can move by itself
Automobiles

4.  The chassis performs the function to support
the entire load & weight of the vehicle along
with passenger as well as goods
 It is the structure upon which all the other
component are mounted
 It has to support both the loads that is static
& dynamic load
(1) Chassis

5.  Full forward chassis ex: bus
 Semi forward chassis ex: tipper
 Monocoque construction/chassis less
construction
ex : all front wheel drive vehicles
Classification of chassis

6. Chassis types

7.  The function of engine / power plant is to
convert chemical of fuel into heat energy &
from heat energy into mechanical energy
 Classification
(1) external combustion engine
(2) internal combustion engine
(2)Engine/power plant

8.  External combustion engines
Are those engines where the power is produced
outside the engine cylinder
Ex :: steam engines
 Internal combustion engines
Are those engines where the power is produced
inside the engine cylinder
Ex:: petrol & diesel engines
Classification

9.  The clutch has to perform 2 functions
(1) to engage / disengage engine power to
road wheels
(2) to transmit the driving shaft from engine
to the transmission system
(3)clutch

10.  Single plate clutch Ex:: ambassador car
 Multi plate clutch
 Diaphragm clutch Ex:: manual
transmission car
 Torque converter clutch/automatic transmission
Ex:: Suzuki vitara, sx4,swift desire
 draw back :: mileage reduces drastically
 Advantages:: we can stop @ any gear
 Cvt = continuously variable transmission
Ex:: kishashi
Clutch classification

11.  The function of transmission system is to
vary the driving torque available @ the engine
to the driving wheels
 It usually consists of 4,5,6,16, sets of gears
depends upon the design of the vehicle &
amount of load to be carried
(4)Transmission system

12.  Sliding mesh
 Ex:: oldest 1930-1940 vehicles
 Constant mesh
 Ex::2 wheelers
 Synchromesh
 Ex::maruti 90% vehicles
 Automatic transmission / Epicyclic gear box
 Ex::desire,a-star,vitara,sx4
Classification

13.  Propeller shaft & drive shaft the function to transmit
the driving torque from gear box to the differential
assembly & from the differential assembly to the
driving wheels
 Propeller shaft:
 It consists of a hollow shaft along with universal
joints @ the both the ends
 the front end is connected to the gear box of output
shaft with the help of the slip joint where as in the
rear end is bolted to the differential tail pinion
assembly shaft is placed @ the angle alpha 30*
 Driver shaft :
 2 drive shaft with triangular ball joints
(5) propeller shaft & drive shaft

14.  The function of differential assembly is to
differentiate the speeds btw both the driving
wheels
 i.e; inner & outer wheels it consists of a
following components mainly
 (1)Differential housing
 (2)Crown wheel assembly/ bevel gear
assembly
 (3)Sun gear & star gears along with cage
assembly
 (4)Spider pin assembly
(6)Differential assembly/final drive assembly

15.  Condition (1)
 When vehicle is travelling over a straight path
 Ans:: In this condition the whole crown wheel
assembly rotates as a single unit as there is no
need of differential btw the driving wheel.
 Condition (2)
 When vehicle takes a turn to left or right
 Ans::In this condition the sun gears & the star
gears begins to the rotates along with the crown
wheel assembly in order to differentiate the
speeds btw inner & outer wheel. there by a
vehicle can take sharp turns within minimum
possible distance.
Working of differential assembly

16.  The function of suspension system is to
suppose the load & weight of the vehicle
along with that provide cushioning effect to
both passenger as well as goods .
 It may either consists of leaf spring or coil
spring or Mac pherson stud assembly along
with oil filled or gas filled shock absorbers
(7) suspension

18.  Leaf spring
 Oil spring
 Independent suspension system / Mac
pherson stud
 Damper
Classification of suspension system

19.  The steering system performs the function to
convert the rotary motion of the steering
wheel into angular turning of front road
wheel
 It may consists of 2 sets of gears
 (1) worm & wheel
 (2) rack & pinion
(8) Steering system

20.  (1) reciprocating ball & nut mechanism
/worm & wheel mechanism
 (2)Rack & pinion mechanism
 (!) manual assisted steering
 ex:: 800,omini,gypsy etc
 (!!) power steering
 (1) hydraulic assisted power steering
 ex::esteem,balano,suzuki grand vitara
 (2) electronic power steering
 ex::swift,sx4,ritz etc
2 types of steering system classification (in maruti
vehicles)

21.  Maintenance is less
 Periodic check is less necessary
 Normally found in light duty vehicles
Electronic power steering advantages

22.  Maintenance is very high
 Periodic checking is necessary
 Normally found in heavy duty vehicles and
trucks
Hydraulic power steering advantages

23.  The function of braking system is to stop/
slow down the moving vehicles within the
minimum possible distance
 Classification
 (1) mechanically actuated
 (2) hydraulically actuated
(9) Braking system

24.  Tandum master cylinder
 Fluid reservoir
 Fluid lines
 Wheel cylinders (drum brakes)
 Brakes calipers (disc brakes)
 Brake liners (drum breaks)
 Brake pads
 Bleeder nipples
 Parking brake cable (mechanically actuated)
Hydraulically actuated/hydraulic breaking system

25.  The function of cooling system is to maintain
the operating temperature of an engine & to
carry away the rated amount of heat away
from the engine
 Normal operating temperature of the engine
is btw 85*c to 90*c
(10) Cooling system

26.  Radiator
 Hoses (1) upper tank hoses
 (2) lower tank hoses
 Thermostat valve
 Water pumps
 Water jackets
 Radiator fan
 Expansion tank
 coolant
Components of the cooling system

27.  To cool the engine coolant
 Dissipated the heat towards the engine
Radiator fan

28.  Increase the boiling point of water up to
(120) degree Celsius
 Increase the freezing point of water up to
(-15) degree Celsius
 It acts as a rust inhibitor
 It acts as a water pump lubricant
 It acts as a leakage detector
 Composition of coolant
 Mono ethylene glycol /alcohol/ether
Coolant (purpose)

29.  Function of lubricating system
 To reduce friction btw 2 surfaces in contact
 To act as a sealing agent(to fill the 0.01 micro
gap btw the cylinder wall and the piston ring
arrangement)
 To provide cleaning action
 To provide cooling action( carry away the
heat)
(11) Lubricating system

30.  Oil sump
 Strainer
 Oil pump
 Oil filter
 Oil gallery
 Path :crank shaft, big end of connecting rod,
smaller end of the connecting rod, piston
pin(wrist pin),piston rings(oil scrappers rings)
Components of lubricating system

31.  Ex:engine oil 20W40
 i.e SAE 20W40 – engine oil
 SAE – society of automotive engineering
 20W40
(-20*c)(winter season)(+40*c)(summer season)
Engine oil grades

32.  Electrical system is required for following
reasons
 (1)starting/cranking
 (2)charging
 (3)ignition system
 (4)heating of the glow plug
 (5)operation of other accessories ex: centre
locking,headlight,sensors etc
(12) Electrical system

33.  Container
 Cell cover
 Vent plug
 terminals
 Plates
 Separator
 Ribs(slot)
 Electrolyte(dilute sulphuric acid and distilled
water)
Battery components

35. Specific gravity of Fully charged
battery =1.260= 12.6 volts
For Over charged battery
=1.300= 13.0 volts
For Fully discharged battery
=1.100=11.0 volts
Specific gravity of the battery is
determined using multi meter
Specific gravity of battery

36.  Check the battery for any mechanical damages
 Top up the battery with electrolyte
 Connect the battery to a battery charger
terminals by connecting positive & negative
terminals of the battery to the charger
 If we are charging a single battery then set the
volts to 120 volts & amps to 2 amp
 The indication of the battery charging can be
made out when gassing takes place
 Disconnect the battery from the battery charger
terminals & allow to cool for about an hour &then
once again check the specific gravity
Battery charging procedure

37.  Ignition key
 Battery
 Starting motor
 (1) solenoid assembly
 (2) shift lever
 (3) housing/outer body
 (4) field winding(series/shunt)
 (5) armature assembly
 (6) commutator
 (7) copper brush(draws current)
 (8) over running clutch
 (9) drive pinion
Starting or cranking

38.  DC generator/ dynamo
 AC generator/ alternator
 Components of DC generator (dynamo)
1. Housing/body
2. Field winding (2 types of winding)
3. Armature
4. Commutator
5. Carbon brush(supplies current)
6. Regulator (3 relay=(1) current ,(2) voltage, (3)
cutoff relay)
Charging system

39.  Components
1. Housing (aluminum housing)
2. Stator winding
3. Rotar
4. Slip rings
5. Rectifier
6. Regulator assembly
7. Diodes (cutoff is done by diodes, it always
allow only 1 directional flow of current from
AC to DC)
AC generator/ alternator

40. 1. Battery
2. Ignition (acts as a step up transformer i.e.,
12v to 25000v)
3. High tension (HT) cord connecting from
ignition coil to the distributor cap
4. Carbon brush
5. Condenser assembly
6. Contact breaker (CB) points
7. High tension cords connecting from
distributor to the spark plugs
8. Spark plug
Ignition system

41.  It can be defined as the exact degree @ which
the spark occurs inside a engine cylinder
 It is expressed in terms of units before top
dead centre
 Ex:1 ignition timing for a carburettor vehicles
is 7* before TDC
 Ex:2 ignition timing for a MPFI vehicles is
5(+/_) 1* before TDC
 Ex:3 ignition timing for a LPG vehicles is 10*
before TDC
Ignition timing

42.  It refers to the amount of degrees the braker
cam rotates from the time the point remains
closed until it opens again
 Dwell angle for 3 cylinder engine is 60(+/-)
2* before TDC
 Similarly for 4 cylinder engine is 50(+/-)
2* before TDC
Dwell angle

43.  Specification
1) For carburetor vehicles .7 to .8 mm
2) MPFI vehicles .8 to .9 mm
3) K series vehicles 1.0 to 1.1 mm
filler gauge is used to adjust spark plug gap
Spark plug gap

44.  Purpose
1) Tire rotation is done to reduce/minimize
the tire wear
2) Wheel balancing to avoid wheel wobbling
3) Wheel alignment to maintain directional
stability
Tire rotation, wheel balancing & wheel alignment

45.  Caster
 Camber
 Toe in or toe out
Factor effecting wheel alignment

46.  The angle formed btw the tire centre line &
the king pin centre line when viewed from
side of the vehicle is known as caster angle
caster

47.  The outward tilt of front road wheels when
viewed from the front of the vehicle is known
as camber angle
 If the tire tilts outward then it is positive
camber
 If the tire tilts in ward then it is negative
camber
camber

48.  The inward or outward tilt of front road
wheels when viewed from top of the vehicle is
known as toe in & toe out
Toe in & Toe out

49. Depending upon the vehicle driving condition
the service types can be classified under 5
categories
 Pre delivery inspection (PDI) service
 Free service
 Paid service
 Brake down service/(maruti on road service)
 Body repair section
 Running repair
Types of services

50. (1)PDI
 Initial inspection of the vehicle for the errors in
new vehicles
(2) Free service
1st free services for 1000km/ within 1month from
the date of sale which ever is earlier
2nd free service for 5000km/ within 6 month
3rd free service for 10,000km/within
1year/12month
Definition : the visit of new vehicle for service
within the 1st 1000km / within 1 month which
ever is earlier from date of sale is known as 1st
free service
Schedule of service

51.  The visit of the vehicle to the workshop after
3 free service/after 10,000km/after 1 year is
known as paid service
 In this service the cost of both there is oil ,
consumables, spare parts& labour charge has
to be paid by the consumer itself
schedule of paid service
Every 10,000km or <<<<

52.  The unintensional or unexpected failure of
vehicle while in transportation / while
running is known as break down service
 Break down is actually caused due to lack of
maintenance or poor maintenance
 In maruti we have for 24 hours on road brake
down service known as MOS

53.  the visit of the vehicle to the workshop for
performing accidental repairs like
denting,painting,tinkering etc . With the help
of special equipments like pneumatic body
pullers, welding machines is known as body
repair section

54.  The visit of the vehicle to the workshop with
in 3000 km after service is termed as running
repair
 Running repair is a serious issue which is
caused due to the incorrect diagnosis by
service advisor/ technician/ electrician

55.  Engine decarbonizing machine
 Pneumatic gun
 Stud compressor
 Brake drum puller
 Brake bleeding machine
 AC refrigerant recharging kit
 Multimetre
 Battery charger
 Battery tester (bosch)
 Hydrometer (suck the water in the battery)
 Refractometre
 Brake fluid tester
 John bin 3d wheel aligner machine
 Hoffman’s tire changer
 Nitrofil nitrogen tire inflactuator
 Hunter’s safe lane report
Special equipments & tools available in workshop

56.  Spot welding
 MIG welding
 Pneumatic body pullers
 3D chassis diagonal measuring machines
Special equipment under body repair

57.  It is the device which mixes both air and fuel
in required proportions before sending it into
engine cylinder
carburetor

58.  Starting circuit
 Idling circuit
 Choke circuit
 Acceleration pump
 High speed full load circuit
 High speed part load circuit
Circuits available in carburetor

59.  NO efficient mixing of air & fuel takes place
 Air & fuel ratio varies from cylinder to
cylinder or not constant in all direction
 Pollution due to the unburnt gases leading to
the emission of carbon monoxide &
hydrocarbon
 Servicing & maintenance is bit complicated
due to minor parts
Draw backs in carburetor vehicles

60.  Control modulus
 Depending upon the vehicle variance the
control modules can be classified under
1. ECM (electronic control module)
2. BCM (body control module)
3. SDM (sensing & diagnostic module)
4. ICM (immobilizer control module)
Introduction to MPFI technology

65.  ECM
 It controls the operation of engine related sensors & actuators
 BCM
 It controls / perform the function to control the total electrical system of
an vehicle like ABS,EPS,auto AC & power windows etc
 SDM
 It acts as a control module to activate the air bags during the collisions/
accidents
 CAN BUS controlled area network
 ICM
 Acts as a control module to prevent vehicle theft by electronically
disabling the engine starting , ignition & fuel supply
 ICATS
 Intelligent computer antitheft system
Function of above component

67.  Absence of Venturi – No Restriction in Air
Flow/Higher Vol. Eff./Torque/Power
 Hot Spots for Preheating cold air
eliminated/Denser air enters
 Manifold Branch Pipes Not concerned with
Mixture Preparation (MPI)
 Better Acceleration Response (MPI)
 Fuel Atomization Generally Improved

68.  Use of Greater Valve Overlap
 Use of Sensors to Monitor Operating
Parameters/Gives Accurate Matching of
Air/fuel Requirements: Improves Power,
Reduces fuel consumption and Emissions
 Precise in Metering Fuel in Ports
 Precise Fuel Distribution Between Cylinders
(MPI)

69.  Fuel Transportation in Manifold not required
(MPI) so no Wall Wetting
 Fuel Surge During Fast Cornering or Heavy
Braking Eliminated
 Adaptable and Suitable For Supercharging (SPI
and MPI)

70.  High Initial Cost/High Replacement Cost
 Increased Care and Attention/More Servicing
Problems
 Requires Special Servicing Equipment to
Diagnose Faults and Failures
 Special Knowledge of Mechanical and
Electrical Systems Needed to Diagnose and
Rectify Faults

71.  Injection Equipment Complicated, Delicate to
Handle and Impossible to Service by Roadside
Service Units
 Contain More Mechanical and Electrical
Components Which May Go Wrong
 Increased Hydraulic and Mechanical Noise
Due to Pumping and Metering of Fuel

72.  Very Careful Filtration Needed Due to Fine
Tolerances of Metering and Discharging
Components
 More Electrical/Mechanical Power Needed to
Drive Fuel Pump and/or Injection Devices
 More Fuel Pumping/Injection Equip-ment and
Pipe Plumbing Required- May be Awkwardly
Placed and Bulky

77.  Also Called Manifold Injection or Single Point
Injection (SPI) or Throttle Body Injection (TBI)
 Injector Usually Upstream From Throttle (Air
Intake Side) or In Some Cases Placed on the
Opposite Side
 Pressures are Low – 2 to 6 Bar. Maybe
Injected Irrespective of Intake Process
 Cost Would be Low

78.  Has Same Air and Fuel Mixing and
Distribution Problems as Carburetor but
Without Venturi Restriction so Gives Higher
Engine Volumetric Efficiency
 Higher Injection Pressures Compared to
Carburetion – Speeds up Atomization of
Liquid Fuel

79.  Also Called Port Injection or Indirect
Multipoint Injection (IMPI) or Simply Multi-
point Injection (MPI)
 Injectors Positioned in Each Induction
Manifold Branch Just in Front of Inlet Port
 Injection at Low Pressure (2-6 Bar)
 Need Not Be Synchronized With Engine
Induction Cycle

80.  Fuel Can Be Discharged Simultaneously to
Each Induction Pipe Where it is Mixed and
Stored Until IVO
 Need Not Be Timed – Requires Low Discharge
Pressures – Injectors Not Exposed to
Combustion Products so Complexity Reduced
– Less Cost

81.  No Fuel Distribution Difficulties Since Each
Injector Discharges Directly Into Its Own Port
and Mixture Moves a Short Distance Before
Entering Cylinder
 Induction Manifold Deals Mainly With Only
Inducted Air – So Branch Pipes Can Be
Enlarged and Extended to Maximize Ram
Effect

82.  Also Called Direct Multi-point Injection
(DMPI) or Gasoline Direct Injection (GDI)
 Injection May be During Intake or
Compression Process
 Increased Turbulence Required
 To Compensate For Shorter Permitted Time
For Injection/Atomization/Mixing Injection
Pressure Must Be Higher

83.  More Valve Overlap Possible So Fresh Air Can
Be Utilized For Scavenging
 Injector Nozzle Must Be Designed For Higher
Pressure and Temperature So Must Be More
Robust and Will Be Costlier Than Other Types
 Position and Direction of Injection Are
Important – No One Position Will Be Ideal For
All Operating Conditions

84.  Air and Fuel Mixing Is More Thorough in
Large Cylinders Than In Small Cylinders
Because Droplet Size is the Same
 Condensation and Wall Wetting in Intake
Manifold Eliminated But Condensation On
Piston Crown and Cylinder Walls

85.  There is Separate Air and Fuel
Metering
 Fuel Metering is Precise Under
All Engine Operating
Conditions

86. 1. CONTINUOUS INJECTION
Injector Nozzle and Valve are Permanently
Open While Engine is Operating
Amount of Fuel Discharged as a Spray is
Controlled by
a. Varying Metering Orifice, or
b. Varying Fuel Discharge Pressure, or
c. Both

87. 2. INTERMITTENT OR PULSED INJECTION
Fuel is Sprayed at Regular Intervals With
Constant Fuel Discharge Pressure
Amount of Fuel Discharged is Controlled By the
Time Period the Injector Nozzle Valve is Open

88. Assume Engine Operates Between 750 (Idling) and
7500 rev/min (Max. Speed)
(1:10 ratio)
In Continuous Fuel Injection:
 Fuel Flow has to vary by a Factor of 1:50 by
Volume using Variable Area Orifice
 Injection Pressure has to Vary by a
Factor of 1:2500 using Fixed Orifice
Or a Combination of Both Variables

89. In Pulsed Fuel Injection:
 Nozzle Valve is Opened For a Short Time
When Fuel Has to Be Sprayed
 Fuel Flow Has to Vary by a Factor of 1:5
(Between Idle and Maximum Speed)
 This Range is Increased Significantly For Cold
Starting Where Control Accuracy Requirement
is Much Reduced

90. 1. Timed Injection
Start of Fuel Delivery For Each Cylinder Occurs
at the Same Angular Point in Engine Cycle –
Could be 60 or 90 Deg. ATDC of Induction
Stroke of Each Cyl.
2. Non-timed Injection
All Injectors Programmed to Discharge Fuel at
Same Time. Each Piston Will be on a
Different Part of the Cycle

91.  Injection System Must Sense Changes to
Influencing Parameters
 Pass Information to a Coordinating System
(Microprocessor or Computer)
 Which In Turn Integrates Individual Signals
and Interprets Fuel Requirements
 Then Signals Injector to Open and Close

92.  Needs are Transmitted by Mechanical,
Hydraulic or Electrical Means to Pumping and
Metering Devices Which Supply Correct
Quantity of Fuel to the Appropriate Injector

93. 1. Engine Speed
2. Amount of Inlet Air (Engine Load)
3. Throttle Position
4. Air Temperature
5. Coolant Temperature
6. Altitude
7. Cranking Speed
8. Exhaust Oxygen Concentration
9. Battery Voltage

94. 1. Electric Fuel Pump
2. Fuel Accumulator – Maintains Fuel Line
Pressure When Engine is Shut Off and
Quietens the Noise Created by the Roller
Cell Pump
3. Fuel Filter - A Pleated Paper or Lint-of-
fluff Type Plus Strainer
4. Primary Pressure Regulator – Maintains
Output Delivery Pressure to be About 5
Bar

95. 5 Push Up Valve – Prevents Control Pressure
Circuit Leakage.
It is a Non-return Valve Placed at
Opposite End of Pressure Regulator
6. Fuel Injection Valve – Valves are Insulated
in Holders to Prevent Fuel Vapor Bubbles
Forming in the Fuel Lines Due to Engine
Heat.
Valves Open at about 3.3 Bar and Spray
Fuel.
Valve Oscillates About 1500 cycles per
second and so Helps in Atomization

96. This is a Driverless Mechanical F.I.S.
Fuel is Continuously Metered in Proportion to
Quantity of Air Induced into Engine
Cylinders
“K” Stands for the German Word for
“Continuously”

97. Considered in 3 Parts
1. Air Flow Measurement
2. Fuel Supply
3. Metering and Injection of Fuel

109. 1. Air Flow Sensor Measures the Throttle
Controlled Quantity of Air Drawn into the
Engine
2. Pressurized Fuel Provided by an Electric
Motor Driven Roller-type Pump Which
Delivers Fuel Through an Accumulator and
Filter to the Mixture Control Distributor
Unit. A Pressure Regulator Maintains the
Fuel Entering the Mixture Control Unit at
Constant Pressure

110. 3. Amount of Fuel Discharged into Air is
Related to Measured Air Flow Signaled to
Mixture Controlled Unit Whose Function is
to Meter Corresponding Quantity of Fuel
Transferred to Injector

117.  MPFI engines depends upon the type of
injection can be classified under 2 categories
1) Throttle body injection
2) Port fuel injection system
Classification under MPFI technology

118.  Injection of the petrol fuel above the throttle
wall is known as throttle body injection
 This system were widely used in olden cars
of foreign countries
 But now it is completely absolute / removed
Throttle body injection

119.  The injection of petrol fuel into the inlet port
is known as port fuel injection system
 This system is widely used in all the modern
vehicles
Port fuel injection system

120.  Sensors
 Are those device which converts mechanical
impulse into electrical signals
 Ex: MAP sensor , IAT sensor etc .
 Actuators
 Are those devices which converts electrical
signals into mechanical impulse
 Ex: injector , IAC valve etc.
Sensors & Actuators

121. 1) IAT ( intake air temperature sensor)
2) IAC ( idle air control valve)
3) TPS ( throttle position sensor)
4) MAP ( manifold absolute pressure sensor)
5) ECT ( engine coolant temperature sensor)
6) CMP ( camshaft position sensor)
7) CKP ( crank shaft position sensor)
8) VSS (vehicle speed sensor)
9) O2 ( oxygen sensor)
10) Knock sensor
List of sensors in MPFI vehicles

122.  Working principle of this sensor is thermistor
 This sensor is located into the air filter
assembly and perform the function to report
to the ECM the exact temperature of suction
air depending upon which the ECM will
control duty cycle and pulse width of
injectors
IAT sensor

123.  Working principle is piezo electric
 This sensor is located in the throttle body &
perform the function to report to the ecm
 The exact amount of vaccum pressure
created inside the intake manifold depending
upon which the ecm has to vary the duty
cycle & pulse width of injector
MAP sensor

124.  Working principle is potentiometer
 This sensor is located @ the opposite end of
the throttle valve & it perform the function to
report to the ecm
 The exact degrees of throttle valve opening &
closing . Depending upon which the ecm has
to vary the duty cycle & pulse width of
injector
TPS sensor

125.  Duty cycle
 It means opening & closing cycle of an
injector.
 Pulse width
 It means the duration of time for the injectors
in MPFI engine remain open or closed
Duty cycle & Pulse width

126.  Working principle is HALL EFFECT
This valve is located under the bottom portion
of throttle body & perform the function to
bypass more air around the valve when the load
on the engine is suddenly increased
 There are 2 cases
1. when switching on the air compressor
2. When parking a vehicle that has an hydraulic
power steering
IAC valve

127.  Working principle is thermistor
 This sensor is located into the thermostat valve &
perform the function to report to the ECM
 the exact temp of engine coolant depending
upon which the ECM has to perform 2 functions
1. To indicate the exact coolant temp in the
instrument panel
2. To switch on or off the electric radiator fan
on temp of fan 98*c
off temp of fan 85*c
ECT sensor

128.  Working principle is HALL EFFECT
 This sensor is located on top of the cam shaft
or @ the opposite end of cam shaft timing
gear & perform the function to report to the
ECM
 The exact degree of intake & exhaust valve
opening & closing time
 Depending upon which the ECM as to vary the
injection timing.
CMP sensor

129.  This sensor is located under the crankshaft
timing gear & perform the function , to report
to the ECM . Exact degrees of cylinder piston
position depending upon which the ECM
alters the ignition timing
 NOTE::
 Both CMP & CKP are very essential for an
engine & the vehicle which are having these
sensor won’t start if the sensor fails
CKP sensor

130.  This sensor is located @ the gear box output
shaft & perform the function to report to the
ecm
 The exact vehicle speed depending upon
which the ECM has to perform 2 functions
1. To indicate the exact vehicle speed &
distance travelled in terms of units (kmh)
2. To provide power steering assistance to
vehicle having EPS
VSS sensor

131.  Chemical used for coating ZIRCONIUM
DIOXIDE
 This exact level/ percentage of O2 level of
present in exhaust gas .
 Depending upon which the ECM maintains the
stiochiometric which is about
 14.7:1 ratio for petrol
 15.5:1 ratio for diesel
O2 sensor

132.  Working principle is piezoelectric
 This sensor is located into the combustion
chamber & perform the function to sense the
exact time of knocking depending upon
which the ECM alters the ignition timing
Knock sensor

133. 1) Blanking (sheet metal cutting)
2) Stamping (molding by pressure)
3) Welding
4) Painting ( electro deposition, intermediate
coat & final coat)
5) Machining
6) Engine assembly
7) Vehicle assembly
8) inspection
AUTOMIBLE production process

134.  Inline
 V shape
 Flat/horizontal opposed/boxer
Engine construction

135.  Total amount of air & fuel sucked inside the
engine cylinder during suction stroke
 K series engines are EURO IV
 Firing order with no distributor 1 4 3 2
k series
 For engine with distribution assembly is
1 3 4 2 .
Cubic capacity

136.  DDLI = dual coil distribution less ignition
 SDLI = single/smart coil distribution less
ignition
 Single over head cam shaft is driven by belt
from crankshaft.
 Double over head cam shaft is driven by
chain from crankshaft.
Spark plug

137.  Twisting / turning force required to move a
object is measured in kg-m.
 Torque=force*radial distance.
Torque

138.  Power obtained @ the engine fly wheel
 P-S is a german term for metric horse power
a different unit of measurement of power
developed by the engine
 1 metric hp = 1ps = .986 bhp.
 PS= PFERDE STARKE
Brake horse power BHP

139.  Is the ratio of bhp(power) to the weight of the
vehicle in tons
 Pwr=bhp/weight of car in tons
 MIL = mal function indication lamp
Power to weight ratio (pwr)

140.  Sedan/notchback
 Hatch back
 Estate /station wagon
 MPV/MUV
 SUV/off road
Types of design

141.  Saloons are basically vehicle with an engine
area, passenger area & boot area all are
separate & with 4 doors
 Ex: esteem ,baleno ,accent etc

142.  Vehicle with an separate engine area but
combined passenger & boot area
 Ex:swift ,ritz ,Zen ,800 etc

143.  Estate are modified saloon vehicles by
combining the boot with passenger area &
extending it till the roof

144.  Engine passenger area & boot area enclosed
together
 Ex: Omni & versa

145.  These vehicle have large tyres,higher seating,
higher ground clearance . The engine area is
separate & the passenger & boot area are
enclosed together
 These are equipped with 4 wheel drive
 Ex: gypsy & grand vitara

146.  Ground clearance::
 Distance btw the ground & lowest portion of
the vehicle that is gear box
 Wheel base::
 Is the distance btw the centre of the front
wheel & the centre of the rear wheel
 Turning radius::
 Radius of the smallest circle in which car can
turn

147.  Hydraulic power steering
 Electronic power steering

148.  Function of power steering is to reduce the
effort applied by the driver while turning the
car.
 Most cars use a hydraulic system which uses
oil & pump , driven by engine
 This system holds good for bigger cars

149.  There is an electrical motor that provides the
necessary assistance for drives while turning
the cars instead of pump & oil set up
 It includes ps control module
 Electric motor

150.  Advantages::
 Puts lesser load on the engine
 Requires no periodic maintenance
 Vehicle speed sensitive
 Self diagnosis capability compact
 Benefits ::
 Better fuel economy
 lower maintenance cost
 Better control
 Faster repairs
 Suitable for small cars

151.  The function of the ABS unit is to prevent
wheel lock up ( skidding of wheel) under
braking
 Wheel lock up (stopping of wheel) is not
desired for the following reasons
1) With the wheel lock up the weight of moving
car slides the car further ,thus increasing
the braking distance
2) As the wheel is stopped , steering the car is
no longer possible
3) Tyre wear out faster

152.  It works on the principle of Pascal law
Which states that when brake is applied the
brake fluid is supplied in same quantity &
results in the locking of the wheel.

153.  155/65 R13
 155 tyre width in mm
 65 aspect ratio (height/width)
 R for radial tyre
 13 rim diameter in inches

154.  It converts exhaust pollutants into harmless
gases
 2 types of catalytic converters
1) 2 way catalytic converter
2) 3 way catalytic converter
2 way converter converts carbon monoxide &
unburnt fuel into carbon dioxide & water
vapour
3 way converter converts carbon monoxide
,unburnt fuel & nitrogen oxides into carbon
dioxide, water & N2
Emission byproducts are co, Nox, hydrocarbon

156.  Over steer ::
 The rear of the car steering a wider path than the
front
 OR the rear end of the vehicle stepping out
 Rear wheel lose traction before the front
 Under steer ::
 The front of the car taking a wider radius cure
than intended
 OR the front of the vehicle running wide
 Also when the front wheel lose traction before
the rear

157.  It is the number used to calculate the wind
drag acting on a vehicle
 The drag coefficient in a function of various
factors like shape of the vehicle , air flow
below & above , ventilation etc .
 The lower the drag coefficient number, the
lower will the aerodynamic drag acting on the
vehicle.
 Thus the vehicle with a lower drag can
perform better in terms of efficiency & speed

158.  To increase downward force & prevent
dragging of the vehicle when vehicles is in
high speed

159.  Coolant & oil mixed & burning of these
mixture in combustion chamber

161.  3 rings
 1st & 2nd rings indicates compression
 3rd ring indicates oil control rings
 Rings are arranged in such a way that it must
be @ an angle of 45* to each other
Piston ring

163.  Use to perform the opening & closing of the
valves during the cycle by connecting the
crank shaft & cam shaft
 Battery led sulphate +ve
 Battery led antimony –ve
 Half shaft is connected to star gear
Timing chain