3reVi STARTUNED Information for the Independent Mercedes-Benz Service Professional 131. December 2007 U.S. $6.00 €12.50 - • Power Windows ^m H • • M • • ^H he First 100 Years • m n IHffiKI^I K1 Volume 7 Number 4 •ilRffl
T O O U R READERS I N T H I S ISSUEWelcome to StarTuned, the 4 KOMPRESSOR KAPUTT?magazine for independent servicetechnicians working on Mercedes- Raising the pressure in an intake system can createBenz vehicles. Your Mercedes-Benz a significant horsepower increase. Supercharging isdealer sponsors StarTuned and one way of accomplishing this. Heres how Mercedes-Benzprovides the information coming manages the boost.your way in each issue.Mercedes-Benz wants to present theinformation you need to know todiagnose and repair Mercedes-Benz 14 A BREATH OF FRESH AIR:cars accurately, quickly and the first MERCEDES-BENZ POWER W I N D O W Stime; text, graphics, on-line and other Regardless of all the advancements in climatetechnical sources combine to make control technology, nothing beats mother natures fresh air.this possible.Feature articles, derived fromapproved company sources, focuson being useful and interesting.Our digest of technical information 26 MILESTONES IN A LEGENDScan help you solve unanticipated FIRST O N E H U N D R E D YEARSproblems quickly and expertly. No other carmaker in this galaxy has a longer or moreOur list of Mercedes-Benz dealers distinguished heritage than Mercedes-Benz. Here is a lookcan help you find Genuine at some milestones reached in the first 100 yearsMercedes-Benz Parts. of that history.We want StarTuned to be bothhelpful and informative, so please letus know just what kinds of featuresand other diagnostic services youd 30 FACTORY SERVICE BULLETINSlike to see in it. Well continue tobring you selected service bulletins These suggestions and solutions for technical problems arefrom Mercedes-Benz and articles from service bulletins and other information published bycovering the different systems on Mercedes-Benz, selected and adapted for independentthese vehicles. repair shops.Send your suggestions, questionsor comments to us at:StarTuned 31 G E N U I N E MERCEDES-BENZOne Mercedes Drive PARTS... NEARBYMontvale, New Jersey 07645Phone: 1 800 225 6262, ext. 2647 Wherever you are in the United States, theres a nearbye-mail: StarTuned@mbusa.com source of genuine factory parts for your customers Mercedes-Benz vehicles.StarTuned is a quarterly publication of Mercedes-Benz USA, LLC ("MBUSA"). No part of this newsletter may be reproduced without the express written permission ofMBUSA. E d i t o r i a l a n d Circulation Offices: 598 Pine Point Drive, Akron, Ohio 44333. Caution: Vehicle servicing performed by untrained persons could r e s u l t in seriousi n j u r y to t h o s e p e r s o n s or o t h e r s . Information contained in this newsletter is intended for use by trained, professional auto r e p a i r t e c h n i c i a n s ONLY. Thisinformation is p r o v i d e d to i n f o r m these t e c h n i c i a n s of c o n d i t i o n s w h i c h may occur in some vehicles or to provide i n f o r m a t i o n w h i c h c o u l d assistthem in proper servicing of these v e h i c l e s . P r o p e r l y trained technicians have the e q u i p m e n t , t o o l s , s a f e t y instructions, and know-how to perform repairscorrectly and safely. If a condition is described, DO NOT assume that a topic covered in these pages automatically applies to your vehicle or that your vehicle hasthat condition. StarTuned is a registered trademark of MBUSA.
STARTUNEDInformation for the Independent Mercedes-Benz Service Professional Mercedes-BenzDecember 2007 U.S. $6.00 € 12.50Group Publisher Editorial Director MBUSA Technical Production ManagerChristopher M. Ayers, Jr. Bob Freudenberger Content Advisor Devon Ayerscayers@cmacomm.com firstname.lastname@example.org Donald Rotolo email@example.com Contributing Editor Donald.Rotolo@mbusa.comSenior Project Director Circulation ManagerTamra Ayers Wade Nelson Project Director Joann Turnertayers@cmacomm.com firstname.lastname@example.org Russell G. Chave email@example.com Contributing Editor Russell.Chave@mbusa.com List Consultant Kerry Jonsson Art Director NFocus firstname.lastname@example.org Jef Sturm email@example.comVisit us at our website www.MBWholesaleParts.com to view this issue and all past issues of StarTuned, along with a wealth of information on Genuine Mercedes-Benz Parts.
FEATURE ARTICLE • Raising the pressure in an < intake system can create ^ L a significant horsepower * increase. Supercharging is one way of accomplishing this. Heres how Mercedes-Benz manages the boost.04 StarTuned
Mercedes-Benzuses a "Roots"type supercharger.It performs wellat low rpm, butgenerates quitea bit of heat inthe intake air,which makesan intercoolernecessary.
SUPERCHARGER In 1998, Mercedes-Benz introduced the SLK and the piston starts to travel upwards toward (170 chassis) into the United States, a light- TDC, creating the compression. The powerweight, nimble, two-seat sports car. Its small size produced by the following piston stroke is limited meant it was not able to fit the six- or eight-cylin- by how much air finds its way into the cylinderder engines that were installed in the C280 and during the intake stroke.C36 AMG models. So, the new four-cylinder, By increasing the pressure in the intake system 2.3L (111) engine was used. While this engine is to something higher than 14.7 psi, we cansolid, a sports car really should offer more per- force a greater quantity of air into the cylinder,formance than an entry-level C-Class (C230). therefore creating more power. Supercharging The solution to this was the addition of forced achieves this by using the engines own power toair induction in the form of supercharging. In 02, drive a belt that spins an air compressor. Thisthe SLK by AMG received a 3.2L supercharged "kompressor" or "blower" forces higher pressureV6, in 03 the C230 got a 1.8L supercharged air into the engines air intake system. This "boost"engine, and all of the AMG 5.5L engines were can produce significant horsepower gains."artificially aspirated" as well. There are limits to this phenomenon, however. This was not a simple matter of bolting on a With too much pressure, the mixture may igniteblower and some plumbing. Managing boost and before the intended time. This pre-ignition (alsominimizing acceleration lag are engineering chal- known as detonation) can quickly destroy anlenges that the Mercedes-Benz engineers dealt engine. This is why on turbocharged and super-with very well indeed. Here well examine the lay- charged engines the compression ratio isout of the supercharging system so that we may reduced. Also, lower octane fuels compound thisbetter understand how to diagnose it when a problem by being easier to ignite. So, there mustproblem occurs. be some pressure limiting feature built into the supercharging system. A pressure "pop-off" valve can be used, but it is inefficient to waste engineSupercharging 101 horsepower to drive a supercharger only to blow-off excess pressure that is not needed. Without getting too deeply into the theory ofsupercharging, we do need to understand thebasic principles so we can diagnose a symptomby isolating its cause. Essentially, as an enginerotates through its four cycles it generates avacuum in the cylinder as the piston dropsto BDC. The atmosphere providesoutside pressure that isapproximately 1 bar or14.7 psi. Thispressure flowstoward thevacuum inthe cylinderthrough theopen intakevalve. At this point the intakevalve closes (depending The addition of a "kompressor"on the camshaft profile and gave the 2.3L performance "scavenging" designed into the system), befitting a sports car.06 StarTuned
Here Is the Recirculating Air Valve Actuator This flap is normally open. A pulse-width modulated signal controls the Pap. The larger the duty-cycle (positive slope) the more the flap is commanded closed. When it is fully closed, all of the intake air goes through the blower to produce boost.A Tale of Two Paths the intake manifold on the drivers side. But how does Mercedes-Benz control the boost pressure in the intake system? You have probably noticed Lets start by following the air flow of thesupercharged 111 engine (2.3L). Of course, a what looks like an electronic throttle assemblyconventional air intake system starts in the air right off of the air-box. This is indeed a similarbox, which houses the air filter. However, from assembly, but it has a different task.here we have two different paths the filtered air 110/2can take. Under acceleration, it is directed downto the back of the supercharger. Mercedes-Benzuses a "Roots" type blower. Interestingly,Gottlieb Daimler installed this type of super-charger on early production industrial engines 19th century, but, of course, engineeringadvancements have increased its efficiencytremendously. The Roots supercharger is a posi-tive displacement pump that starts to build pres-sure at relatively low rpm (about 2,000). It doesheat up the pressurized air it produces, though,so the air needs to be cooled by means of anintercooler, which may be of the air-to-air orair-to-water type. The SLKs air-to-air unit travelsalong the lower front bumper and resurfaces onthe drivers side of the engine, entering the This is the path airflow SIM4LEthrottle plate. Later model larger displacement takes when the Recirculating N3/10supercharged engines use a air-to-water Air Flap is closed. All intakeintercooler, but more on that later. air is routed through the The SLK uses a "fly-by-wire" electronic throttle blower so maximum boostor EA (Electronic Accelerator) mounted on top of can be achieved. StarTuned 07
SUPERCHARGER 110/2 Here, the Recirculating Air SIM4LE Flap is open, so any boost N3/1 generated is recycled back ° into the airbox. Therefore, no positive pressure is built up in the intake system. The second air path engineered into the sys- tem is dependent upon a Recirculating Air Flap assembly. It acts just like an electronic throttle plate except that when it is closed, intake air is forced through the supercharger and pressurized air is sent to the engines intake system. If too much boost pressure is being made for the throt- tle application (determined by monitoring CPS, TPS and MAP sensor signals), the Recirculating Air Bypass valve is opened to allow air to bypass the blower and continue straight to the intake manifold, or to allow boost pressure to bleed off back through the airbox. This reduces the amount of air passing through the blower and reduces boost pressure. The Recirculating Air Bypass assembly is not just open or closed. The ME control unit can vary the position of the valve to maintain consistent boost pressure. This helps reduce lag when changing from deceleration to acceleration. It also reduces boost if the level becomes dangerous to the engine. On early 111.973 engines, an electromechani- cal clutch was used, much like an A/C compres- sor clutch. This would allow the "kompressor" to be disengaged entirely, therefore not generating any boost or causing any parasitic drag at low rpm. Above 2,200 rpm, the clutch is engaged StarTuned
This engine was generating too much boost from a Recirculation Air Flap actua- tor that was sticking closed. The engine started missing as injectors were being shut off and timing was being retarded.and boost is produced. In 2001, Mercedes-Benzphased out the clutch mechanism, so boost ismanaged by the Recirculating Air Flap alone.Okay, Now How Do I Fix It? So what are some of the service issues weregoing to face? Let us start with codes. If you pulla code P0805 and/or P1235, then youre dealingwith overall supercharger function. Connecting apressure gauge to the intake system will tell us ifwe are achieving proper supercharger pressure.Here in the United States, the 92 to 94 octanegasoline available will not allow any forced airinduction vehicle to produce excessive boostwithout fear of detonation, so boost is limited tojust under eight psi. These codes are letting usknow that even though rpm, throttle applicationand load show boost conditions, proper boost isnever achieved. This could be caused by a bind-ing Recirculating Air Flap, but more than likely iscaused by an air leak in the air intake system. Atorn boot or a leak at any plumbing joints willoften lead to these codes, which may be accom-panied by a driveability problem such as a sud-den loss of power, or a "bogging." Introducing smoke into the intake system maynot indicate the source of the leak since the rub-ber may only leak when significant pressure isapplied. Keep in mind worn or broken motormounts can add stress to air intake plumbing. StarTuned 09
SUPERCHARGER Monitoring boost pressure with a gauge while between the clutch and the ECMs driver. under load is a good way to determine if boost Another set of codes that are part of the pressure is being lost - j u s t verify proper opera- forced air induction system are P0803 andtion of the Recirculation actuator. P1243. These are for Recirculating Air Flap oper- If you pull codes P0806 and/or P1236, they ation. This actuator is normally open. A pulse-deal with supercharger clutch operation. There is width modulated signal is sent from the ECM to no speed sensor for the blower, so proper opera- the recirculating actuator commanding it to closetion is determined by monitoring the supercharg- and produce boost pressure. As a general rule,er clutch electronic signal. You can monitor the the wider the duty cycle (positive slope) of thevoltage and current draw of the clutch and check signal the more the flap is commanded closed.for proper activation. This is most easily achieved The ECM monitors the boost pressure, throttleat the powertrain control unit. For example, on a angle and mass air flow signals and determines if98 SLK 230, power is provided to the clutch the flap is working. If you feel comfortable usingfrom fuse F2 in the relay module (mounted in the a dual-trace scope, you should scope the pres- under-hood, passenger side electrical housing). sure sensor and the flap actuator command sig-This fuse also powers up the 02 sensor heaters nal. As long as rpm is increasing, the pulse width and the Canister Vent Shut Off valve, so be on the command line should increase as the careful of these other codes. By evaluating the signal voltage on the pressure sensor indicates wiring diagram we see that the control unit, con- more boost pressure. If the pressure is dropping nector F, pin 21 is the ground control of the while the duty cycle command is increasing, clutch. By monitoring the voltage and amp draw either the actuator flap is malfunctioning, of the solenoid we should be able to determine or boost pressure is leaking out of theproper clutch operation and isolate a fault intake system. 10 StarTuned
SUPERCHARGER )C H I PROBE BIQOmVDC 1HPR( On this scope, we are monitoring HV T r i g i A l +1DIV T ^^~ni the voltage pattern (top trace) and amperage pattern (lower trace) of a supercharger clutch. Notice how I* •• 1 »>!llHHI<W • -*""*• "^" %l<l l*«,..v*^y irv»i>,M>i the amperage draw peaks at just over 3.0 amps. About 3.5 amps is the maximum you should see on a good one. rubbing together. However, the supercharger assembly does require special lubrication. As per the StarTuned article "Liquid Diet" (archived on the website in the June, 2006 issue), the C230K and SLK230 have their own lubricant, Part Number 000 989 62 01. It is added through the fill/inspection plug hole. The 3.2L and 5.5L AMG engines use a different supercharger lubri- cant - Mobil Jet Oil II. Also, the 3.2L and 5.5LWhat If I HaveAP04IO? AMGs have a Charge Air Cooler Circulation pump. This uses liquid coolant to keep the tem- On the 111 engine (2.3L), the supercharger perature of the supercharger within bounds. Asdoubles as the secondary air pump. This means mentioned earlier, the 3.2L and 5.5L engines bythe supercharger clutch must be activated for 30 AMG use an air-to-water intercooler, so be sureto 90 seconds after the vehicle is started to sup- to drain coolant and bleed the cooling systemply the exhaust system with fresh air to aid in when servicing the intercooler. As with any otherheating up the catalytic converters. So, diagnos- belt-driven component, belt wear and propering a secondary air injection code includes test- tension are important.ing supercharger function. Activating the blowerclutch and the secondary air control solenoidwhile at idle should pump fresh air into the In Conclusionexhaust. You can monitor additive (idle) adapta-tion to see that fuel is being added. Remember While Mercedes-Benz engine management sys-to have the fuel system in closed loop so that tems are very good at monitoring problems andfuel trim adaptation is functioning. You can also indicating faults through their self-diagnosticwatch 02 sensor voltage to see that it drops to functions, a driveability problem may still need under 100mv indicating a lean condition. some good old fashioned hands-on testing. Monitoring boost pressure, sensor signal voltage and solenoid voltage control/amperage drawHow Do / Prevent Costly may be the final steps in verifying the cause ofSupercharger Repairs? the customers complaint. Of course, there is always the most important ingredient: a thorough By its design, the Roots supercharger has a understanding of the system at hand.non-contact air gap so rotor vanes should not be12 StarTuned
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FEATURE ARTICLE Regardless of all the advancements in climate control technology nothing beats mother natures fresh air. With the added complexity of convertible tops and other body control features, however, the simple act of opening a window becomes a symphony of computer-controlled communication.14 StarTuned
werWindows Gone are the days when push-button controls supplied power or ground to power window motors. In an effort to add features to these well-engineered vehicles, computer controls were enlisted. In any system, if a computer is in control of outputs, these outputs can be manipulated with a variety of inputs. As far back as 1990, Mercedes- Benz introduced the option of a "Comfort System," at the heart of which was the Convenience Control Module. This module not only controlled power door locks and the sunroof, but also communicated with the Anti-Theft Alarm Control Unit. These advancements meant more features for the owner, but they also meant a greater diagnostic effort to keep these features functioning. Lets look at the various systems Mercedes-Benz has used. Today, just opening a window is part of a highly-orchestrated electronic process. StarTuned 15
This connector is for a power window motor with a motor position sensor. In this application, pins #3 and #6 operate the window. The other pins are for the position /speed sensor. Pin # / is the ground, pin #4 is the power supply, and pins #2 and #3 are the signal wires used for position.Evolution vs. Revolution windows are controlled by a Power Soft Top control module. The reason for this is the power Previous to 1990, Mercedes-Benz power windows have to work in concert with thewindow controls were merely switches that convertible top. When the driver commandstoggled power or ground to each motor. By the convertible top to open, each window isswitching the polarity, the motors would drive opened to provide clearance so the windowthe windows either up or down. Each front power doesnt rub against the door seals.window switch had five wires: one each for The front power window switches on thesepower and ground, two to control the motor, and computer-controlled systems still have five wires,one for illumination. The rear switches had six but a few of them now serve a different purpose.wires, the additional one coming from the front We still have one wire providing power to illumi-drivers switch to control the motors. nate the switch. We also have one wire devoted As mentioned earlier, the computer-control to ground. The other three wires come directlyrevolution began in 1990. The 124 and 129 from the Convenience Control Unit, not thechassis were the first vehicles to have the power power window motors. These wires have signalwindows controlled by an electronic unit. The voltages on them. By toggling the switch up or 124 chassis power window circuit is controlled down, one of these three wires would beby a Convenience Control Unit, as we said, and connected to the ground wire effectivelythe 129 chassis is slightly different in that it is a grounding this signal. When the Convenienceconvertible. With convertibles, the power Control Unit receives this ground signal, it16 StarTuned
provides the proper polarity to the window motor position/speed sensor. This sensor determinesto drive the motor up or down, depending on when the window is reaching its travel limit, andwhich signal was brought to ground. We have stops the motor (more on this later). In 94, thethree signal wires, one is to command the motor entire Mercedes-Benz line-up (except convert-up and the other is to command the motor down, ibles) utilized the Comfort System and theso whats the third one for? Convenience Control Unit to control the sun/moon roof as well as the power windows.Value-Added Features Another interesting feature is the pair of signal wires from the PSE control unit to the Mercedes-Benz added a new feature. Convenience Module. In the lock mode, if theSwitching this third wire to ground signals the key is held in that position the PSE module willcontrol unit to command the window motor all signal the Convenience Module to close anythe way open. The driver no longer has to hold open windows. Knowing how these features workdown the button to pay a toll. This "Auto Down" will help in diagnosis of a problem with windowfeature allowed the driver to get back to driving. operation.Keep in mind that the 126 and 201 chassis never At the same time that computer-controlledgot the "Comfort System," having instead con- features reduced the amount of wiring in aventional power window wiring. vehicle, paradoxically it also increased the Starting in 1992, Mercedes-Benz introduced amount of wiring in a vehicle by adding morethe 140 chassis. This being the companys luxury control units. A greater effort was required toflagship, it included more control of the power reduce wiring complexity. Lets see howwindow circuit. The motors included a four-wire Mercedes-Benz chose to achieve that. (Continued on page 20) Here we have the result of "resistive multiplexing." Four wires control the front power windows on a two-door convertible. The brown wire is ground, and the grey and green wires carry the signals that command the motors, grey for the drivers side and green for the passengers side. StarTuned 17
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POWER W l N D O W S (Continued from page 17)New Layout Power Window Diagnostics With the introduction of the 170 (SLK) and 208 With power window systems previous to 1990, (CLK) chassis, a new power window switch was testing is straightforward. You could remove theadded. In fact, a whole new layout was launched. door panel and check for power and ground toToo many body control features are present for the motor, but that would involve additional laborone Convenience Control Unit to handle. that we have not yet justified. Also, banging on Mercedes-Benz chose to distribute more control the inner door panel to see if you can loosen upunits throughout the vehicle. Instead of the a stuck armature is at best inconclusive. WeComfort System using the Convenience Control would suggest you start by checking fuses. ThisUnit as a single central control, the Comfort requires the least amount of labor. However, youSystem features were distributed to several com- may still have to diagnose why the fuse blew.ponents such as the Door Control Modules. We would suggest you continue testing at theThese modules control the power window motor, power window switch. It is easier to get to andmirror heating and mirror retract functions. More you can perform many more electrical tests with-features would be added later. It would also relay out removing the door panel. By removing thememory function requests to other control units ashtray and storage tray (if applicable), you cansuch as those for the telescopic steering wheel remove the shifter cover and expose the windowand power seat module. Since the power seat switch wiring. From here, you can determine ifand memory switches are mounted in the dri- the switches have the power supply and groundvers side door, all of the wiring is directed to the they need. We can also test the switch contactsdrivers side door module. This relays the seat providing power and ground to the motor.commands through the CAN bus to the power Additionally, we can bypass the switch contactsseat control unit, which eliminates the need to with jumper wires and verify that correcting arun wiring outside of the door directly to the seat power or ground problem will operate the motor.module, thus helping to reduce wiring. If we verify power and ground to a motor and it In an additional effort to reduce wiring, the still does not work, we can now justify removingpower window switch no longer has five wires the door panel for further testing.attached to it, but only three. One wire is still If you have a power window problem with theused for illumination. That leaves two wires to Comfort System, there are three steps you caninform the door control module to open the win- take to isolate the cause. Step one is to performdow, close the window, or open the window all functional testing of other related components. Ifthe way. This is achieved with "resistive multi- the drivers side window motor is not workingplexing." Multiplexing is the process of using with the manual push button, you may want tomultiple signals on a single wire. Resistive multi- see if you can command the motor open orplexing is all about changing the signal voltage by closed using the Comfort System. By turningchanging the resistance applied for each switch the key in the door lock, or holding the remoteposition. In other words, with the switch in one button down, you can command the windowsposition, the first wire carries reference voltage, closed (and open in some models). If the windowwhich is sent through a resistor to the second functions at this point, you know that the windowwire that is grounded, generating a specific sig- motor and a portion of the Convenience or Doornal voltage. By putting the switch in a different Control Module are working fine. If the windowposition, a different resistor changes the refer- does not function, you may want to focus yourence voltage to a different signal voltage. When testing on the door control unit and the windowthe control unit sees these different voltages it is motor. programmed to respond with a different output Another weapon we have in our troubleshoot-for each voltage input. This is how we can have ing arsenal is Star Diagnosis. The ability to use athree different signals on one wire, therefore scan tool to monitor inputs and bi-directionally reducing the number of wires in the vehicle. control outputs is a tremendous advantage over20 StarTuned
In this test of the reference voltage from the door control module, we see approximately 10 volts. Pushing the button for the drivers side power window should make this voltage reading change.basic electrical testing. Of course, scanning for know in which direction the motor is moving andany trouble codes may give an indication of how far its gone. It also counts pulses to checkwhere to begin your testing regimen. the speed of the glass to detect blockage in the If you monitor the power window switch inputs, up direction.you can see if the door control module recog- As well as verifying that you have a power andnizes the signal change. If you see the change, ground command to the power window motor,you can move on to the output of the window you may have to verify that the position/speedmotor. If you do not see the switch input change, signals are indicating motor position to theyou now know the problem is in the switch. At control unit. This would be your third step in thethis point, you need to verify if the switch is diagnostic process, verifying your scan tool find-malfunctioning or if there is a wiring problem. ings with electrical testing. This may involve Dont forget that there is more involved in the some additional labor to remove panels and getpower window motor of the 140 and 220 chassis. access, but you should be able to give an esti-These motors have a position/speed sensor built mate on the time involved and get it approved.into them. If the symptom is erratic position of Functional testing, scan tool diagnostics andthe window, you may have a bad position/speed electrical testing will ensure that your diagnosissensor. This is a four-wire sensor, one wire is the is accurate and timely. 12V power supply, one is ground, and the last twocarry the signals back to the control unit. If youscope these wires, you will see that they carry 5V Now We Actually Have To Fix Itsquare wave signals. The signals are out of phase by 50%, so you will observe them alternating back Once you have determined what the problemand forth. The control unit memorizes the square is, you now have to fix it. If you isolated thewave position and counts the square waves to problem to a control unit, you simply have to22 StarTuned
This is the result of pushing the power window button in the up position. The voltage on the signal wire has indeed changed. When the door control unit sees this specific voltage, it will command the motor up.replace it. Very often when replacing a control produces uses mounting bolts and clips to hold itunit, you have to version code it. Different on. Some other models use guides that slide intooptions may have been installed on this vehicle channels in the door frame, so sometimes theyand to make sure these features work, the new have to be maneuvered in a particular directioncontrol unit has to be "personalized" to this for removal. Once the panel is off, you have toparticular vehicle. This process is known as contend with the sound-proofing material. Thisversion coding. Most often, the Star Diagnosis can be a plastic sheet, or a foam insert glued toscan tool will download the programming that is the door frame. Care should be taken during itsalready in the old control unit. After the new unit removal so it can be reinstalled properly duringis replaced, the scan tool will then upload the reassembly. At this point you will need to knowprogram to it. Now, the new unit will have the how the power window motor is serviced.same programming function as the old unit. If On some models, the motor is replaced. Onthe problem is in the switch, then simply replac- other models, the motor and regulator assemblying the switch is all you have to do. In some are replaced as one unit. Check your serviceolder models, coding can be done manually. information. Sometimes the window needs to be Replacing the power window motor is a little in a particular position in order to be removed.more involved. First, you have to remove the door This may be a problem if the motor is malfunc-panel. This is a cosmetic piece, so you want to tioning and is not stopped in that position. Youknow exactly how it is to be removed so its not may have to disassemble the assembly inside thedamaged. Also, since it is a cosmetic piece, many door and/or drill out additional access holes toof the mounting bolts and nuts are hidden behind remove a stuck motor.plastic covers. Take the time to evaluate your Upon reassembly, lubricate sliding componentsservice information and you will save time and with light grease to reduce the chances of themoney. Almost every door panel Mercedes-Benz regulator binding. Any friction in the regulator will StarTuned 23
Here we have theresult of moving theswitch in the downposition. Notice how onthe same wire we havea different voltage.When the door modulesees this voltage readingit commands themotor down.These are the mountingpoints for the motorRemoving the three Torxscrews will release themotor. But if the newpart is an assembly, youwill have to drill out therivets that mount theregulator to the doorframe. Rivets give moreclearance than a nut andbolt, so stick with rivets.
Here is the regulator assembly in the door. The channel going across the bottom of the scissors arms needs to be lubricated as these parts slide in the channel. If you have to replace the regulator assembly, you must separate the glass from the channel and support the glass. You will also have to drill out the rivets that secure the assembly.increase the load handled by the window motor. to four seconds. This will need to be done forThis can cause premature failure, or it can cause each control unit/window combination, and onthe "excessive force limiter" to kick in and stop some models the doors must be closed for it towindow operation. Also, these regulator units are work. Now, each control unit knows the motorssometimes mounted with rivets instead of bolts are at their upper limit and can start using thein low clearance applications. The rivets have to position/speed sensor to operate the automaticbe drilled out and the proper size rivet has to be features. This procedure is not required on theused to reattach the assembly so nothing comes new S-Class and CL.in contact as the window is being operated. "/ Need To CheckThe OilFinal Touches In Your Power Windows" Mercedes-Benz recommends that wedisconnect the battery when the power window We would be remiss if we did not inform you ofis serviced. This action, or replacing the control a special protection option that is NOT availableunit, will put the windows out of "sync" with the in the U.S.: hydraulically-operated windows! Thecontrol unit. If the power windows are not door control module operates a valve block thatsynchronized, then the automatic features will uses hydraulic fluid pressure, provided by anot work. On most models, to synchronize the pump, to open and close the power windows.windows with the control unit manually, push the This is a special option that most of us willup button only to the first detent until the never see, but we felt it was our responsibility towindows are closed and hold the switch for two inform you that this technology exists. StarTuned 25
FEATURE ARTICLEMilestones in a LegendNo other carmaker in this galaxy has a longer or more distinguishedheritage than Mercedes-Benz. The following is a look at somemilestones reached in the first 100 years of that history:1885 - On August 29, Gottlieb Daimler of Cannstadt, Germany, is granted a patent on a motorizedbicycle, the worlds first vehicle powered by a four-stroke internal combustion engine.1886 - On January 29, Karl Benz of Mannheim, Germany patents the three-wheeled Benz Motorwagen- the worlds first viable automobile. Later that year, Daimler builds the first four-wheeled car. With 1.5hp, it had 50% more power than the Benz, so the horsepower race had begun.26 StarTuned
s First Hundred Years1888 - Steinway & Sons, the New Yorkpiano maker, obtains the rights to allDaimler patents in the U.S. with theintention of producing engines and carsin this country. This is the first exampleof a strategy thats now become a trend.1894 - In France, the first-ever sanc-tioned automobile race is won by aDaimler-powered car. 1895 - Benz & Co. produces the firstinternal-combustion-powered bus. In thefirst U.S. race (Chicago to Waukegonand back), a Benz comes in second. 1901- Daimler introduces a revolutionary front engine/rear drive car1900 - Benz replaces the tiller with the with four cylinders, four-speeds, a honeycomb radiator, and pneumaticsteering wheel, and becomes the largest tires. Austro-Hungarian businessman Emil Jellinek, an unofficial agentautomobile manufacturer in the world, for Daimler, orders 36 on the condition that the model carry the namedelivering 603 cars. "Mercedes" after his daughter.1905 - The Steinway deal comes to fruition with the 1909 - The Blitzen Benz establishes the worlds landproduction of American Mercedes cars in a Long speed record, which the car holds for 16 years.Island City, NY, factory. This continues through 07.1910 - At Daytona Beach, Barney Oldfield upsthe worlds land speed record to 129 mph in a200 hp Benz.1926 - Daimler and Benz merge to formMercedes-Benz.1931 - The SSKL produces 300 hp and tops outat 150 mph. StarTuned 27
FIRST ONE HUNDRED YEARS1936 - Mercedes Benz builds the first diesel powered automobile. Above: Diesel Patent 1958 - Mercedes-Benz is first with gas shocks. 1965 - Daimler-Benz AG becomes the largest manufacturer of commercial vehicles in Europe. 1970 -B pioneers ABS and air bags. 1985 - The company shows off its first ASR (Acceleration Slip Reduction) system.1954 - The Mercedes Benz 300SL Gullwing is produced withmechanical gasoline fuel injection (similar to a diesel system,its direct!).Today - Many Mercedes-Benz cars have become classics, and all models tend to last much longer than othervehicles. So, chances are youll be repairing or restoring M-B cars that are decades old. If that idea makes youworry about parts availability, weve got good news: Visit MBUSA.com/classic, or call 1-866-MBCLASSIC, andyoull be well on your way to tracking down the genuine Mercedes-Benz part you need.28 StarTuned
Enticingly graceful and dynamic. Strong support, too. PERFORMANCE VALUE SERVICE WARRANTY Every part comes with the reassurance of a strong 12 month/unlimited mileage limited warranty-with additional coverage for engines and transmissions* Unlike any other.The part is just part of the story. The precise fit and superior performance of a Genuine Mercedes-BenzPart is a given. But equally important is that each Genuine Mercedes-Benz Part-down to the last nut,bolt and gasket-comes with the unmatched technical support and expertise from your dealer and Mercedes-Benz. All evidence of our constant dedication to supporting your business in more and betterways than anyone else. And thats the best part. Visit mbwholesaleparts.com or contact your dealer. Mercedes-BenzSee your Mercedes-Benz dernier for detail* and a copy a)lite. Men ah* Here Replacement Parts Untiled Warranty.
STARTUNEDFACTORY SERVICE BULLETINS"ESP Visit Workshop" 1 Remove the excess length of the heat-shrinkable tube on the ground cable lug so that a completeDisplayed In Instrument Cluster ground connection can be established (Figure 2). Note: Do not damage the coating on the groundAll Model 203 Vehicles, cable lug. Additionally, ensure that the heat-shrink-As of August 1,2001 able tube is only removed in the area of the screw attachment point.Series Production If "ESP - Visit Workshop" is being displayedin the instrument cluster, and for vehicles withan automatic transmission, the selector levercannot be moved from position "P" after theengine is started, and various fault codes arestored in the relevant control units, perform 2.Tighten the nut on the ground bolt (W70) to 8 Nm.the following repair.Note: In vehicles equipped with tire pressureloss warning system this function will also not Thumping Noisebe available. from Front Axle The conditions listed above are caused by aninadequate ground connection at the ESP (W70) Modelground point (Figure 1, arrow) due to the heatshrinkable tube protruding under the ground I 64.122/175/177/186/822/871,cable lugs attachment point. Model 25 1.122/1 65/175/177 If there are thumping noises coming from the front axle when driving over bumps, retighten the bolted connections to 200 Nm between the tor- sion bar and the stabi- lizer bar and between the torsion bar and the suspension strut to resolve.30 StarTuned
STARTUNEDGENUINE MERCEDES-BENZ PARTS... NEARBY Belmont Palo Alto Walnut CreekAlabama Autobahn Motors Park Avenue Motors Mercedes-Benz of Walnut CreekDothan 650-637-2333 650-494-0311 925-937-1655Mike Schmitz Automotive Beverly Hills Pasadena West Covina334-794-6716 Mercedes-Benz of Beverly Hills Rusnak/Arcadia Penske Motorcars 310-659-2980 626-795-8004 626-859-1200Hoover Buena Park PleasantonCrown Automobile Colorado House of Imports Mercedes-Benz of Pleasanton205-985-4200 714-562-1100 925-463-2525 Colorado SpringsHuntsville Calabasas Riverside Mercedes-Benz of Colorado SpringsMercedes-Benz of Huntsville Mercedes-Benz of Calabasas Walters Auto Sales & Service, Inc. 719-575-7950256-837-5752 818-591-2377 951-688-3332 Denver Carlsbad RocklinMobile Murray Motor Imports Hoehn Motors Von Housens MotorsMcConnell Automotive 303-759-3400 760-438-4454 916-630-8877251-476-4141 Chico Sacramento LittletonMontgomery Courtesy Motors Auto Center Mercedes-Benz of Sacramento Mercedes-Benz of LittletonJac< Ingram Motors 530-893-1300 916-924-8000 303-738-7700334-277-5700 El Dorado Hills San Diego Westminster Mercedes-Benz of Eldorado Hills Mercedes-Benz of San Diego Mercedes-Benz of Westminster 916-567-5100 358-279-7202 303-410-7800 Encino San Francisco Mercedes-Benz of Encino Mercedes-Benz of San Francisco Connecticut 818-788-0234 415-673-2000 San Jose DanburyAnchorage Escondido Beshoff Motorcars Mercedes-Benz of DanburyMercedes-Benz of Anchorage Mercedes-Benz of Escondido ^08-239-2300 203-778-6333907-277-3383 760-745-5000 Fremont San Jose FairfieldFairbanks Fletcher Jones Motor Cars Smythe European Mercedes-Benz of FairfieldAuto Service Company 510-623-1111 408-983-5200 203-368-6725907-456-6217 Fresno San Luis Obispo Greenwich Mercedes-Benz of Fresno Kimball Motor Mercedes-Benz of GreenwichChandler 559-438-0300 805-543-5752 203-869-2850Mercedes-Benz of Chandler San Rafael Glendale Hartford480-403-3400 R.A.B. Motors Calstar Motors New Country Motor Cars 818-246-1800 415-454-0582Phoenix 860-278-2000Phoenix Motor Santa Barbara602-264-4791 Laguna Nigue! Santa Barbara Auto Group New London Mercedes-Benz of .aguna Niguel 805-682-2000 Carriage House of New LondonPhoenix 949-347-3700 860-447-3361Schumacher European Santa Clarita480-991-1155 La Jolla Mercedes-Benz of Valencia North Haven Heinz Gietz Autohaus 858-454-7137 661-753-5555 Mercedes-Benz of North HavenTucsonMercedes-Benz of Tucson 203-239-1313 Los Angeles Santa Monica520-886-1311 W.I. Simonson Downtown L.A. Motors Delaware 213-748-8951 310-526-4700Arkansas Manhattan Beach Santa Rosa Milford Carwell Smothers European I.G. BurtonFayetteville 310-303-3500 707-542-4810 302-424-3042Mercedes-Benz of Northwest Arkansas479-521-7281 Modesto Signal Hill Wilmington Modesto European Mercedes-Benz of Long Beach Mercedes-Benz of WilmingtonLittle Rock 209-522-8100 562-988-8300 302-995-2211Rivers de Motors501-666-9457 Monterey Stockton Mercedes-Benz of Monterey Berberian European MotorsCalifornia 831-375-2456 209-944-5511 ClearwaterAnaheim Newport Beach Thousand Oaks Lokey MotorMercedes-Benz of Anaheim Fletcher Jones Motor Cars Silver Star A.G. 727-530-1661714-777-1900 949-718-3000 805-371-5400 Coral GablesArcadia Oakland Torrance Bill Ussery MotorsRusnak /Arcadia Mercedes-Benz of Oakland Mercedes-Benz of South Bay 305-445-8593626-447-1117 510-832-6030 310-534-3333 Palm Springs Van Nuys Daytona BeachBakersfield Mercedes-Benz of Palm Springs Keyes European Mercedes-Benz of Daytona BeachMerceces-Benz of Bakersfield 760-328-6525 818-461-3900 386-274-4775661-836-3737 StarTuned 3 I
Fort Lauderdale Atlanta Northbrook Louisville Mercedes-Benz of Fort Lauderdale RBM of Atlanta Autohaus on Edens Tafel Motors 954-462-4381 770-390-0700 847-272-7900 502-896-4411 Fort Myers Atlanta Orland Park Louisiana Mercedes-Benz of Fort Myers Mercedes-Benz of Buckhead Mercedes-Benz of Orland Park 239-433-8300 404-846-3500 708-460-0400 Alexandria Walker Automotive Fort Pierce Augusta Pekin 318-445-6421 Mercedes-Benz of Fort Pierce Mercedes-Benz of Augusta Suds of Peoria 772-466-7000 706-860-1111 309-347-3191 Baton Rouge Mercedes-Benz of Baton Rouge Fort Walton Beach Columbus Peru 225-490-3101 Quality Imports Mercedes-Benz of Columbus J.P. Chevrolet GEO Nissan 850-863-2161 815-223-7000 Lafayette 706.256.6100 Moss Motors Gainesville Duluth Springfield 337-235-9086 Duval Motorcars Isringhausen Imports Atlanta Classic Cars 352-332-7571 217-528-2277 Metairie 770-279-3600 Mercedes-Benz of New Orleans Jacksonville Sycamore 504-456-3727 Macon Brumos Motor Cars Brian Bemis Imports Jackson Automotive Group Shreveport 904-724-1080 815-895-8105 478-477-4858 Holmes European Motors Lakeland Westmont 318-212-1212 Savannah Central Florida Eurocars Mercedes-Benz of Westmont Critz 863-688-8111 630-654-8100 912-354-7000 Maitland Bangor Mercedes-Benz of Orlando Quirk Auto Park of Bangor 407-645-4222 207-941-1017 Evansville Honolulu Falmouth D-Patrick Melbourne Mercedes-Benz of Honolulu Prime Motor Cars 812-473-6500 Mercedes-Benz of Melbourne 808-592-5600 207-510-2250 321-956-0600 Fort Wayne Miami Mercedes-Benz of Fort Wayne Maryland Mercedes-Benz of Miami 260-432-7200 Boise Annapolis 305-919-8000 Lyle Pearson Indianapolis Mercedes-Benz of Annapolis 208-377-3900 World Wide Motors 410-268-2222 Naples Mercedes-Benz of Naples 317-580-6810 317-924-5321 Pocatello Bethesda 239-643-5006 Euro Motorcars Robert Allen Auto Group Lafayette 208-232-1062 301-986-8800 Orlando Mike Raisor Imports Mercedes-Benz of South Orlando 765-448-4582 Cockeysville 407-367-2700 Mercedes-Benz of Hunt Valley Mishawaka 410-666-7777 Pembroke Pines Arlington Heights Gurley-Leep Motorwerks Mercedes-Benz of Pembroke Pines Mercedes-Benz of Arlington Heights 574-254-7130 Germantown 954-517-8600 847-259-4455 Euro Motorcars Germantown, Inc. Schererville 240-686-1300 Pensacola Barrington Napletons Auto Werks of Indiana, Inc Centennial Imports Motor Werks of Barrington Hagerstown 219-865-3800 850-432-9903 847-381-8900 Mercedes-Benz of Hagerstown 301-733-2301 Pompano Beach Bourbonnais Mercedes-Benz of Pompano Napletons Autowerks Owings Mills 954-943-5000 815-933-8221 Davenport R & H Motor Cars Lujack Motorwerks 410-363-3900 Sarasota 563-388-8610 Champaign Mercedes-Benz of Sarasota Salisbury Sullivan-Parkhill Imports 941-923-3441 Mercedes-Benz of Salisbury 217-352-4161 Des Moines St. Petersburg Mercedes-Benz of Des Moines 410-548-3411 Crown Eurocars Chicago 515-278-4808 Mercedes-Benz of Chicago Silver Springs 727-526-3738 312-944-0500 Iowa City Herb Gordon Auto Group Tallahassee Carousel Motors 301-890-3030 Capital Eurocars Hoffman Estates 319-354-2550 850-574-3777 Mercedes-Benz of Hoffman Estates 847-885-7000 Tampa Boylston Mercedes-Benz of Tampa Lake Bluff Wagner Motor Sales 813-870-0010 Knauz Continental Autos Shawnee Mission 508-869-6766 847-234-1700 Aristocrat Motors West Pam Beach 913-677-3300 Haverhill Mercedes-Benz of Palm Beach Lincolnwood Smith Motor Sales of Haverhill 561-689-6363 Loeber Motors Wichita 847-675-1000 978-372-2552 Scholfield Auto Plaza 316-688-5000 Hyannis Loves Park Albany Trans-Atlantic Motors Napletons Autowerks Albany Motorcars 815- 636-6600 Kentucky 508-775-4526 229-883-2040 Marion Ashland Lynnfield Alpharetta Foley-Sweitzer Motor Sales Giant Auto Group of Ashland Flagship Motorcars RBM of Atlanta - North 618-997-1313 606-329-2288 781-596-9700 678-637-2333 Naperville Bowling Green Natick Athens Buchanan Imports Mercedes-Benz of Natick Mercedes-Benz of Naperville Mercedes-Benz of Athens 508-655-5350 630-305-4560 270-745-0001 706-549-6600 Lexington Somerville Atlanta Normal James Motor Chambers Motorcars of Boston Mercedes-Benz of South Atlanta Suds Motor Car 309-454-1101 859-268-1150 617-666-4100 770-964-160032 StarTuned