March 2008 StarTuned Magazine

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March 2008 Mercedes-Benz StarTuned Magazine

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March 2008 StarTuned Magazine

  1. 1. STARTUNED" Information for the Independent Mercedes-Benz Service Professional ^H iHHtan March 2008 U.S. $6.00 € 12.50V Bluetec^Y ABS/ESP Panels Volume 8 Number
  2. 2. T O O U R READERS I N T H I S ISSUEWelcome to StarTuned, the 4 MERCEDES-BENZ BLUETECmagazine for independentservice technicians working on Diesel redux, thanks to intelligent engineering.Mercedes-Benz vehicles. Cleaning up diesel emissions requires adopting a numberYour Mercedes-Benz dealer of overlapping approaches.sponsors StarTuned andprovides the information comingyour way in each issue.Mercedes-Benz wants to present the 12 GET A GRIPinformation you need to know todiagnose and repair Mercedes-Benz Electronic driver aids have clearly helped reduce trafficcars accurately, quickly and the first incidents over the past decade, but they dont do muchtime; text, graphics, on-line and other good when theyre not working properly.technical sources combine to makethis possible. Feature articles, derivedfrom approved company sources,focus on being useful and interesting. 22 BEAUTY IS ONLY SKIN DEEP:Our digest of technical information W O R K I N G W I T H A L U M I N U M PANELScan help you solve unanticipatedproblems quickly and expertly. The quest for reduced weight has led auto manufacturers toOur list of Mercedes-Benz dealers the use of aluminum, and Mercedes-Benz has been in thecan help you find Genuine forefront of this trend for decades.Mercedes-Benz Parts.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 to These suggestions and solutions for technical problems arebring you selected service bulletins from service bulletins and other information published byfrom Mercedes-Benz and articles Mercedes-Benz, selected and adapted for independentcovering the different systems on repair shops.these vehicles.Send your suggestions, questionsor comments to us at: 31 G E N U I N E MERCEDES-BENZStarTuned PARTS... NEARBYOne Mercedes DriveMontvale, New Jersey 07645 Wherever you are in the United States, theres a nearbyPhone: 1 800 225 6262, ext. 2647 source of genuine factory parts for your customerse-mail: StarTuned@mbusa.com 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 I 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 those persons 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.
  3. 3. STARTUNEDInformation for the Independent Mercedes-Benz Service Professional Mercedes-BenzMarch 2008 U.S. $6.00 € 12.50Group Publisher Contributing Editor MBUSA Technical Production ManagerChristopher M. Ayers, Jr. Wade Nelson Content Advisor Devon Ayerscayers@cmacomm.com wnelson@cmacomm.com Donald Rotolo dayers@cmacomm.com Donald.Rotolo@mbusa.comSenior Project Director Contributing Editor Circulation ManagerTamra Ayers Kerry Jonnson MBUSA Project Manager Joann Turnertayers@cmacomm.com kjonnson@cmacomm.com Russell G. Chave jturner@cmacomm.com Russell.Chave@mbusa.comEditorial Director Contributing Editor List ConsultantBob Freudenberger Ray Fisher Art Director NFocusbfreud@cmacomm.com rayfisher@cmacomm.com Jef Sturm jsturm@cmacomm.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.
  4. 4. FEATURE ARTICLEMercedes-BenzBLUETE€
  5. 5. Diesel redux, thanks to ent engineerin Mercedes-Benz is leading automobile manufac- turers in the re-introduction of diesel passenger vehicles to North America. First, the E320 CDI (W211) debuted in June, 2005 powered by the OM 648, an inline six-cylinder common-rail diesel equipped with a Diesel Oxidation Catalyst. In Model Year 2007, the OM 648 was replaced by the OM 642 V6, which first appeared in the E320 BLUETEC. This engine does not use the additive AdBlue®, but does use a Diesel Oxidation Catalyst, NOx Storage Catalyst, Diesel Particulate Filter (DPF) and a Selective Catalytic Reduction Catalyst (SCR). This is known as the Bin 8 diesel. The OM 642 was also available in the GL, M- and R-Classes, but is not a BLUETEC as it is in the E-Class. This is a BIN 10 diesel. The vehicles were badged as 320 CDI, and have a DOC and DPF, but no SCR. They also require Ultra Low Sulfur fuel. Cleaning up diesel emissions requires adopting A new V-6 meets EPA a number of overlapping approaches. Extremely Tier 2 Bin 5 "50-State" high levels of EGR combined with a reduced compression ratio curtails the production of NOx. requirements. A "regular" oxidizing catalyst combusts remaining hydrocarbons. A particulate filter traps soot. For Tier 2 Bin 5 vehicles, an SCR catalyst, combined with urea injection on the 2009 models, transforms oxides of nitrogen into elemental nitrogen and water. How does all this work, and what are the implications for the Independent Mercedes-Benz repair facility? StarTuned 05
  6. 6. The E320 went from an inline six to o V6 in 2007-2008.Exhaust Gas Recirculation occasionally required to keep these diesels at optimum performance - and prevent throttle Lets begin with EGR. Since EGR gases are valve actuators from sticking.oxygen poor, theyre inert when it comes to com- The new V6 is equipped with an EGR valve withbustion. Inert gas, by displacing the oxygen-rich a lift sensor, EGR intercooler, mass air flow sen-air-fuel charge, keeps peak combustion tempera- sor and throttle valve actuator. The cooled EGRtures down. This reduces the formation of NOx. gases are introduced after the throttle valveIntercooling EGR gases makes them even more actuator. When EGR is active, the ECM knowseffective in controlling NOx production, especially the quantity of EGR entering the engine by thewhen EGR flow rates of 30-50% are used. amount of lift measured by the sensor, and also As with gasoline engines, EGR gases tend to knows how much fresh air is entering the engineleave carbon deposits on everything they come from the mass air flow sensor. This helps ininto contact with. Cooling EGR aggravates the calculating the amount of fuel to be injected.problem since it tends to precipitate out acidic To determine DPF regeneration, the amountcompounds, which would otherwise remain in of backpressure before and after the DPF isgaseous form. Mercedes-Benzs response is to measured by the differential pressure sensor.use a corrosion-resistant stainless steel Regeneration can be spontaneous (if tempera-intercooler. Intercooling creates the additional tures in the DPF reach burn-off), or triggered byissue of contributing to the total heat load a the diesel ECM. Problems can arise if the vehiclediesel engine must dissipate. Consequently, is not driven for a sufficient amount of time tocleaning EGR passages, valves, and maintaining complete a successful regeneration. If thisthe optimum performance of cooling systems are occurs several times, the DPF can be overloadedlikely to be important services for Independent and the MIL will trigger. Using SDS, the techni- Mercedes-Benz repair facilities. cian can force regeneration to occur during a The second issue associated with EGR and test drive.diesels is convincing EGR to flow into the intake Two variants of the BLUETEC technology weremanifold. Theres little or no manifold vacuum to initially developed: the NAC+SCR system, whichcoax EGR gas out of the exhaust and into the met Euro IV emissions standards and was goodintake. The solution Mercedes-Benz adopted is enough for 45 of the 50 US States (Tier 2 Bin 8),adding an ECM-controlled electric throttle in and the AdBlue® system, with urea injection (seeorder to create manifold vacuum on demand. sidebar). AdBlue® cars will be introduced inIntake manifolds exposed to high levels of EGR the 2009 model year and meet emissionscan be expected to foul, and cleaning may be requirements in all 50 states (Tier 2 Bin 5). Both06 StarTuned
  7. 7. technologies demand the use of Ultra-Low Sulfur Exhaust temperatures are boosted by injectionDiesel (ULSD) fuel, which became the standard of additional fuel into the cylinders. The oxidizingat American pumps in 2005-2006. catalyst will turn this overly-rich mixture into the In both systems, exhaust leaves the engine and extremely hot exhaust flow needed to regeneratepasses through a Diesel Oxidation Catalyst the DPF. Ideally, regeneration should occur while(DOC), which "combusts" carbon monoxide and driving at highway speeds so there is plenty ofunbumed hydrocarbons. Next is the NOx airflow around the DOC and DPF. That meansAbsorber Catalyst, or NAC, which removes and little or no risk of igniting shrubbery or brushtraps oxides of nitrogen. During periods of lean beneath the vehicle, nor of causing customeroperation, NOx is stored; under richer operating concerns. Regeneration should be totallyconditions (which can be created by manipulat- transparent to the driver. However, a boosteding the fuel injection) the NAC undergoes a idle speed or other alteration of engine "feel"regeneration process and releases a small may occur, causing driver concerns. Any sort ofamount of ammonia into the exhaust. The fuel or oil leak, such as a sticking injector orammonia is stored downstream in the Selective failed turbo seal could have extremely seriousCatalytic Reduction (SCR) catalyst, which uses it consequences at regeneration time. If a fuelto further reduce NOx. Mercedes-Benz engineers injector is questionable, it should be replaced.had hoped to achieve 50-state emissions with In order to detect backpressure across theNAC+SCR, however, barely missed. Hence, DPF, measure temperatures, and inject urea intoAdBlue®. the SCR, pressure sensors and other items will Oxidizing catalysts are nothing new, and have to be located directly in the exhaust stream,should pose little or no service challenge for a necessarily hostile environment. Logically,techs. Not so a diesel particulate filter (DPF). these sensors should fail at about the same rateWhen sufficient particulate matter has as oxygen sensors and DPF sensors on gasolineaccumulated in the DPF, and an increase in engines, and should trigger similar codesback pressure is detected, regeneration is allowing ease of diagnosis.called for. Regeneration involves boosting the Other BLUETEC issues independent repairtemperature of the exhaust to the point where shops may have to deal with include the use, orsoot accumulated in the DPF gets incinerated misuse, of biodiesel fuels. According to MBUSA,into ash. Think of it as a self-cleaning oven. B5 biodiesel is approved for CDI diesel without Intelligent glowplugs stabilize combustion. StarTuned 07
  8. 8. BLUETECAn oxidizing Oxhti&ng gofajjrifc GOOWFU^catalyst and SCRCatalyst clean upemissions.affecting the warranty. Biodiesel must adhere to controls the current applied to each glow plug,ASTM D6751 and in addition have the necessary and incorporates fail-safe features, such as shortoxidation stability to prevent damage from circuit detection.deposits or corrosion. Whether or not all B5biodiesel available at the pump meets theserequirements is unclear, and this situation may The New V6confuse owners. A related requirement is theuse of engine oil meeting American Petroleum The 2007-2008 E320 BLUETEC boasts accel-Institute (API) rating CJ-4 to prevent ash from eration comparable to the gas-engined E350plugging the particulate trap. six-cylinder a result of the diesels whopping 388 lb. ft. of torque (as compared to 258 in the gasInstant Start System models). That figure is only three lb. ft. short of the E550 V8. It is a completely different engine BLUETEC diesels incorporate an Instant Start from whats found in the 2006 E320 CDI, whichSystem (ISS) with glow plugs that can reach sported an inline six.operating temperatures in two seconds or less. The new 3.0-litre V6 diesel features four valvesAt temperatures above five deg. F. no waiting is per cylinder. It is built on an aluminum block withrequired before the engine can be cranked. The cast-in steel cylinders, with an 83 mm bore andglow plugs are controlled by a module which may "undersquare" 92 mm stroke. A balance shaftutilize them not only in starting situations, but located between the cylinder banks counter-whenever their use could stabilize combustion, rotates at the same speed as the crankshaft tosuch as in extended idling in extremely cold smooth the V-6 out. Twin overhead camshafts inweather. For example, whats known as each cylinder bank operate the intake and"post-glowing" will keep the glow plugs heated exhaust valves, with the intake cams driven by afor a brief period after engine startup to achieve double chain that also drives the balance shaft.smoother operation and reduce emissions. A gear on each intake cam, in turn, drives theA module, which communicates with the ECM, exhaust cams. StarTuned
  9. 9. Mercedes-Benz engineers found that Impressionsthrottling one of the two diesel intake ports oneach cylinder at light loads added slight So much for emissions, what about perform-turbulence that helped optimize the combustion ance? As numerous automotive writers haveprocess and further reduce fuel consumption commented, "This aint your daddys diesel." Theand exhaust emissions. gut-wrenching torque the new diesels are able to While many diesel engines have compression provide at low rpm make them as much of aratios higher than 20:1, Mercedes-Benz engi- performance option as an economy option in theneers found with the Garrett GT20V variable- minds of many. Turbocharging makes the newgeometry turbocharger, the engine is more diesel engine just as fuel efficient as the full sizeefficient and produces less emissions utilizing a hybrids offered by other manufacturers, especial-compression ratio of 16.5:1 (boost goes up to ly during highway travel. Who would ever have29psi). The turbo uses a VNT (Variable Nozzle used "diesel" in the same sentence as "sport",Turbine). The engines electronics control the or "luxury"? Tire-burning torque, great fuelVNTs vanes to suit the load. The intake charge mileage, lack of smoke - will owners even bepasses through an air-to-air intercooler lowering able to tell this is a diesel?the air temperature by up to 150 deg. F. for The answer is yes. On a cold morning, thereincreased charge density. will still be enough clatter to tell that this is a The E320 BLUETEC uses the latest version of diesel engine. Windows shut, drivers will seldomthe Mercedes-Benz Common Rail Direct Injection pause to think, "Im driving a diesel." As with all(CDI) system, which keeps the fuel pressure at turbocharged engines, there may still be slightup to 23,000 psi. The BLUETEC V6 is fitted with lag between stabbing the pedal and the vehiclepiezoelectric injectors that work significantly launching. But according to many who havefaster than magnetic solenoid-based injectors, driven these cars, the "diesel disadvantages"allowing up to five injection events per combus- have been minimized to the point where they aretion event. So called "Pilot Injection" events inconsequential - and more than made up forreduce the noise (clatter) associated with diesels by the tremendous fuel economy these fullby slowing the rapid increase in pressure and size vehicles can deliver, as much as 36 mpg,temperature associated with a single highway.injection event. BLUETEC technology Exhaust-gas treatment of the E 320 BLUETEC eliminates particulates and NOx. advanced DctJOx catalytic convener Sf.V? Mlalytic axmslei StarTuned 09
  10. 10. I, $F*BLUETEC was originally a consortium of Mercedes-Benz,Volkswagen, BMW and Daimler-Chrysler Perhaps one of the most compelling arguments ammonia enables the SCR catalyst to reducefor "going diesel" with Mercedes-Benz is that NOx emissions to a level even lower than theunlike domestic manufacturers who were NAC-SCR system. AdBlue® is carried in a heatedrequired to re-tool and build completely new on-board tank, which should be replenishedengines and emissions systems in order to whenever the car is serviced.meet 50-state requirements, Mercedes-Benzs A gallon of AdBlue® fluid should last approxi-BLUETEC technology, including AdBlue®, is mately 2,500 miles. Should a sensor detect aalready in use in tens of thousands of commer- low level, a dash warning light will be illuminated,cial trucks in Europe. As a result, American and other consequences may be added to theconsumers are not being asked to be guinea pigs program. The EPA doesnt want diesel ownersfor testing new emissions technologies - as the failing to refill it. The AdBlue® tank utilizes aowners of some domestic diesel trucks appear special coupler that mates with the refill bottle,to have been. thus preventing filling errors. BLUETEC is a BrandAdBlue®:What is it? A consortium of Mercedes-Benz, BMW, AdBlue® is the brand name for the Daimler-Chrysler, and Volkswagen initiallyMercedes-Benz flavor of urea injection. collaborated to create emissions controlAmmonia (NH3) created by the injection of liquid technologies for diesel engines in order to meeturea into the hot exhaust stream combines with ever-tightening particulate and NOx standards,NO and NOx to produce H20 and N2 - harmless both in Europe and in North America. "BLUETEC"water and elemental nitrogen (N2 makes up was the result. Of the original consortium mem-approximately 78% of the earths atmosphere). bers, Mercedes-Benz is the only manufacturerUrea injection allows manufacturers to "virtually putting the BLUETEC badge on its vehicleseliminate" all NOx produced by internal equipped with this technology. M H Mcombustion engines. The AdBlue® system places the diesel Visit us at our new website www.MBWholesaleParts.comoxidation catalyst and particulate filter in a to view this article and all past issues of StarTuned,single "can." Ammonia is supplied by injecting a along with a wealth of information onconcentrated urea solution also called AdBlue® Genuine Mercedes-Benz Parts.upstream of the SCR catalyst. The addition of10 StarTuned
  11. 11. • Strikingly seamless and shapely. Nicely priced, too. A VALUE j- Cnmpethively priced Genuine. MercMles-ttmz Headlamps and Tail Lights thoroughly tested to protect against moisture, vibration and temperature, extremes - help enxwe tluir one of the premiere, autntnohiles in the world remains durable, remains pure, and retains ils value. Unlike any other.The enduring value of Genuine Mercedes-Benz Headlamps is crystal clear. Our headlampsoffer a new vibration-resistant construction to eliminate flickering on bumpy roads, with aprecision fit that produces minimal wind noise —and a ventilation system to minimize inner-lensmisting. All proof of the innovation and lasting quality rarely found in non-genuine parts. Sohelp your customers see the light. Visit mbwholesaleparts.com or contact your dealer. Mercedes-Benz
  12. 12. FEATURE ARTICLE 120 140 ^100 :/80 Wl 1 . R^i G rip" tA The ASR warning light will illuminate when the system is commanded not to function, either through the "ASR Off" switch, or if there is a fault in the system. When the light comes on while driving, it does not mean there is a DTC in the system. It means there is a problem with traction at that time.2 StarTuned
  13. 13. 30 35 x100 Electronic driver aids have clearly helped continue to rotate and retain grip. Since tractionreduce traffic incidents over the past decade, hasnt been lost, steering control is possible.but they dont do much good when theyre not The computer can reapply the brakes andworking properly. Keeping our customers continue the slowing-down process. This patternMercedes-Benz vehicles functioning in the occurs several times a second, graduallysafest possible manner should be our goal. stopping the vehicle in a controlled manner.So, heres how ABS/ASR and ESP systems As in the case of fuel injection, the computerwork and how to repair them. can monitor sensor inputs, look at its pre-pro- Anti-Lock Brake systems (ABS) have been grammed set of responses, and manipulatearound for decades. In a panic stop, the driver, output controls to further enhance the stoppingnot being properly trained, applies the brakes as ability of the vehicle. Since a computer can reacthard as possible. This causes the brakes to to these changes quicker than any driver can,overpower the grip between the tire and the braking distances are reduced while steeringpavement. The wheels are now locked and control is maintained. Believe it or not, thissteering inputs prove futile. The driver has lost simple explanation can be applied to even thecontrol of the vehicle. most complicated integrated systems: inputs, Using a computers high-speed data process- logic, and outputs. Knowing how these functioning capabilities, however, programming can together will allow you to test them. This,reduce brake fluid pressure at individual wheels coupled with an understanding of the computersduring a panic stop. This allows the tires to logic, lets you predict and test output controls. StarTuned I 3
  14. 14. ELECTRONIC DRIVER AIDSThe Power in Power Brakes master cylinder). On later models with ASR or ESP, all of the control units are unified into one Before we get started on ABS/ASR/ESP, we ESP/ASR/BAS control unit. Another input (eithershould discuss BAS (Braking Assist System). to BAS or ESP control systems) is the MembraneThis is the power in your power brakes. It is still Travel Sensor. This monitors the position ofvacuum assisted, but this simple system adds the booster diaphragm. If it detects suddenadditional assist when needed. The brake boost- movement of the membrane, it knows the brakeser is exposed to normal atmospheric pressure on were applied suddenly. The solenoid valve (in theboth sides of a diaphragm with the engine off. booster) is then opened allowing full atmosphericWhen the engine is started, manifold vacuum is pressure into the brake pedal side of the brakeapplied to both sides of the diaphragm. When the booster. With full manifold vacuum on the masterdriver applies the brakes, atmospheric pressure cylinder side of the diaphragm and full atmos-is applied through a metered orifice to the brake pheric pressure on the other side, the largerpedal side of the diaphragm. This reduces difference in pressure moves the diaphragm withvacuum to about 11 to 12 in. Hg. This differential greater force toward the master cylinder, thusin pressure forces the diaphragm to move in the increasing braking assist. On smaller enginesdirection of greater vacuum or lower pressure, such as in the SLK230, there is an additionalwhich would be toward the master cylinder side vacuum pump to supply sufficient assist.of the booster. This is normal power assist. Within a Mercedes-Benz booster with BAS The ESP, ASR andthere is a release switch and a solenoid valve. BAS Lights Are All On!The switch indicates when the brake pedal isreleased. This switch input is sent to the BAS Of course, the BAS system will not work ifcontrol unit (often mounted underneath the there is a failure with a component such as the release switch, the solenoid valve or the membrane travel sensor. Other outside influ- ences such as the brake switch (not present on the very latest models) can set a code and turn on all of these warning lights. The brake switch on a Mercedes-Benz is a double-throw switch. It has one set of contacts that are normally open (NO) and another that is normally closed (NC). These switch contacts reverse position when the brakes are applied. Scan data can be used to monitor these switch inputs. To test these switches directly you will probably have to look in multiple diagrams. One brake switch contact could be connected to various control units, such as the illumination module for brake light activation, and the other switch contact could be connected to theHere we have the dual output brake switch. Electronic Traction Support module (ETS) onOne switch contact will be normally open vehicles with four-wheel drive. They could also go(NO), and the other will be normally closed directly to the ESP/ASR/BAS module, so make(NC). You can use the scan tool to watch this sure you know the system you are working on.input, but a DMM will tell you if the switch One easy way to check which systems are in acontact is poor. particular vehicle is to simply look for the various14 StarTuned
  15. 15. Since the control unit is so easy to get to, you can measure the resistance of the wheel speed sensors rightfrom the connector. This not only checks the sensor resistance, but it also checks the wiring. This testingdoes not apply to Active Wheel Speed sensors.warning lights coming on in the instrument sine wave. This AC sine wave indicates thecluster during the key-on bulb check. In later speed of the wheel. If the frequency of the sinemodels, the brake switch input is normally sent wave increases, then the wheel has picked upto the ESP/ASR/BAS module and is communi- speed. If it decreases, then the wheel is beingcated to other control units through the CAN. slowed down. Some models such as the C- and CL-Class inThe Essence ofABS,ASR, and ESP 2001 and the S-Class in 2000 started using what is called an active wheel speed sensor. This has no reluctor or tone wheel, instead using Some of the most critical components in any magnets in the wheel seal (be gentle with themof these systems are the wheel speed sensors. during service) to cause magnetic switching andThey often double as the vehicle speed sensor generate a DC square wave. With any of theseinput and their signals are transferred to the sensors at each wheel the ABS control unit canother control units through the CAN. Wheel determine if any wheel(s) are slowing down fasterspeed sensors live in a harsh environment. than any of the other wheel(s) while under brak-Mounted on the wheel spindle, they are exposed ing. This would indicate different wheel speeds,to high temperatures, moisture, road salt and which means some of them are losing traction.debris, and brake dust. They are AC pulse The ABS control unit can then isolate the onesgenerators, so when scoped they produce an AC that are "locking up," and reduce and apply StarTuned 15
  16. 16. ELECTRONIC DRIVER AIDS This control unit is one of many on the power-A more accurate way to test a wheel speed train CAN. This ASR control unit has tractionsensor is to check how much AC voltage it control, but in this 97 S320 does not havegenerates while spinning the wheel. Here, IV ESP. Notice how easy it is to perform electri-AC is being produced by spinning the wheel cal testing at this unit. Under "Diagnostics,"by hand. Once again, this does not apply to youre given the pin voltages to test for.Active Wheel Speed sensors. control unit can either retard timing, or closebrake pressure as necessary to bring the vehicle the throttle plate to reduce power output. In theto a controlled stop. case of deceleration, if the ASR control unit A second step in assisting the driver is through detects a difference in rear wheel speed com-ASR. If the wheel speed sensors can determine if pared to vehicle speed it can request the MEone or more wheels are slowing down too fast, control to open the throttle to reduce enginethen it stands to reason that a computer could braking. This is referred to as EBR, or Enginedetermine if the wheel was accelerating faster Braking Regulation. As you can see, with thethan the others, otherwise known as wheel slip. integration of all these systems CAN communica-In the event of this phenomenon, the ASR mod- tion is critical to keeping those warning lightsule can isolate the brake fluid circuit and apply off, so an advanced scan tool such as thebrake pressure (stored in the system) to the Mercedes-Benz Compact III would be awheel(s) that is/are slipping. This is roughly the tremendous advantage in this area of diagnosis.same action as an ABS stop, but this time the Keep in mind there is also an ASR "Off" switch.brake is not depressed and the vehicle is Switching the system off may help you isolateaccelerating. This is never more evident than the cause of problem.when accelerating or decelerating in snow. As mentioned earlier, monitoring wheel speed Mercedes-Benz has addressed this problem is critical to these systems functioning properly.with Electronic Traction Support. This system can You need to know how to test these sensors.detect wheel slippage between the two driven One of the first steps you should take is to scanwheels and apply the brake to provide even the computer for codes. Mercedes-Benz elec-power distribution. In addition to brake applica- tronic control systems are capable of detectingtion, the ASR unit can convey to the ME (Motor many abnormalities even if they are minorElectronics) to close the throttle. This is referred enough not to warrant illuminating the warningto as Engine Torque Reduction (ETR). The ME lights. Another step in the diagnostic process is,16 StarTuned
  17. 17. through our scan tool, monitoring the wheelspeed sensors. Of course, during any test drivebe mindful of safety, especially while evaluatingscan data. Its best to have someone else drivewhile you monitor data; perhaps the customercould drive while he or she is explaining to youwhat he or she feels while driving the vehicle.The scan tool is also useful for checking variousswitch inputs such as the brake and releaseswitches. If you get to a point where the scantool has given you all the direction it can, youmay have to electrically test each component. As already mentioned, Mercedes-Benz vehicleswill either have AC pulse generators for wheelspeed sensors, or Active Wheel Speed sensors,which generate a DC square wave. Even thoughits a square wave, the principle remains thesame. The faster the wave, the faster the wheel A/though you see a control unit-type plug, itis traveling and visa versa. With the AC wheel is only for the hydraulic solenoid assembly.speed sensors you can start off with a resistance This component houses the brake fluidtest to make sure you do not have a shorted sen- control solenoids. The unit that controls thesor, but it is best to monitor AC voltage while hydraulic assembly is mounted elsewhere.spinning the wheel by hand. Each wheel shouldproduce a similar AC voltage - between .5 and 1.5V, depending on how fast youre spinning them. Sensors may have different resistances and AC voltage output, so its best to compare one side of the vehicle to the other. In the case of the active wheel speed sensor, a graphing multi-meter or lab scope will illustrate the wave pattern. If this is not available to you, a DMM capable of DC V, Duty Cycle and Frequency will allow you to monitor the consistency of the signal. If you detect the DC voltage dropping out, the duty cycle changing significantly, or the frequency changing rapidly, you probably have a bad sensor. Keep in mind that these are three- wire sensors that have a five-volt reference and a ground as well as a signal line. Things Are Getting Out Of Control!One way to determine what variations are onthe system you are working on is to look at To further enhance driver control, ESP wasthe warning lights during a bulb check. You introduced to coordinate the multiple electroniccan see that this vehicle has BAS, ESP (which control units. The BAS, ABS, ASR, and EBR makemeans it has ASR also) and ETS. If these up the ESP system. These systems work togetherlights stay on with the engine running, you to assist the driver in maintaining control of thedefinitely have a fault in the system. vehicle in low-traction conditions. There are a (Continued on page 20) StarTuned 17
  18. 18. WHY BUY GENUINE? Replace -We replace more parts than aftermarket brands. Engineered - Designed to meet original OEM drawings. Manufactured - Made with same OE components as factory parts. Assembled - Completely assembled from components and not just repaired. New-Tested to new unit standards. Improved Technician Efficiency Without the need to assemble the Reman A/C Compressor with Clutch, technicians can get right to installing the entire Compressor assembly. Competitive Pricing so theres only one part number to order. ^ Quality Reborn All internal components are function-tested during the manufacturing process. 100% replaced O-rings, snap rings and other wear parts. Each compressor undergoes complete quality assurance testing for performance and output. Assembled to OE specs for testing and measuring.
  19. 19. Compressor with Clutch Conversion PART NUMBER MODELS YEAR 260E 1987-1989 300CE 1988-1993 INTRODUCING: NEW APPLICATIONS 300E/TE 1986-1993 300SB SEL 1988-1991 300SL 1990-1993 PART NUMBER MODELS YEAR A 000 230 05 11 80 350SD 1991 C240/C320/S430 350SDL 1990-1991 A000 230 91 11 80 S500/CL500/CLK320 2004 E320 1994-1995 SL320 1994-1997 E320/E500 2003-2006 SL600 1996-1997 A001 23012 11 80 CLS500 2006+ 400E/ 500E 1992-1993 500SL 1990-1993 ML350/ML500/ML55AMG 2003+ A 000 230 06 11 80 E420 1994-1995 A001 230 28 11 80 G500/G55 (NOT G55K) 2003+ E500 1994 SL500 1994-1999 A001 230 68 11 80 ML320/ML430 UP TO 2000 190D 1986-1989 S55AMG/CL55AMG 2003-2005 190DT/300DT/TDT 1987 190E 1985-1993 A000 230 90 11 80 C240/C320 UP TO 2003 260E 1987-1989 300CE 1988-1989 CLK320 2003 A 000 230 1111 80 300D 1987-1993 300E 1986-1992 A000 230 78 11 80 C32AMG KOMPRESSOR 2002-2004 300SE 1988-1992 300SEUTE 1988-1991 C230K M271 E300D A000 230 97 11 80 (VIN RANGE SPECIFIC) 2004 1995 C220/ C280 1994-1995 S600/CL600 2001+ A000 230 1311 80 C36AMG 1995 A001 230 01 11 80 S65AMG/CL65AMG 2005+ 300SD 1992-1993 E55AMG 2004-2006 300SE/ 600SEC 1993 600SEL 1992-1993 CLS55AMG 2006 A 000 230 17 11 80 S320/ S350D 1994-1995 S420 1997-1999 A001 2301411 80 E350/E550 2007 S600 1994-1996 CLS550 2007 CL600 1998-1999 S320 1995-1999 E320CDI 2005-2006 A 000 230 22 11 80 S350D 1995 CLK550 2007 S600 1996-1999 CLK55AMG 2003+ 190D 1986-1989 A001 230 19 11 80 190DT/300D/DT/TDT 1987 SLK55AMG 2005+ 190E 1985-1993 260E 1987-1989 C55AMG 2005+ A 000 230 24 11 80 300CE 1988-1989 300E 1986-1992 C230K M271 A001 230 55 11 80 (VIN RANGE SPECIFIC) 2004 300SE 1988-1992 300SDL 1986-1987 300SEU TE 1988-1991 420SEU560SEC/SEL 1986-1991 A 000 230 25 11 80 560SL 1986-1989 400SE Compressor Oil 1992 J- 400SEU 500SEC 1993 A119 230 00 11 80 500SEL 1992-1993 • Superior performance over ordinary PAG S420/ 500 1994-1995 • Designed to last the lifetime of the compressor C280/C43 AMG 1998-2000 • Unsurpassed lubricity for wear protection CLK320 1998-2003 M-Compressor Oil! CLK430 1999-2003 R134a ND8 A/C Compressor Oil CLK55 AMG/ML320 2001-2002 8.45 fl. Oz. A 000 230 70 11 80 E320 1998-2002 PN: BQ 113 0001 E430/E55AMG 2000-2002 ML430 1999-2001 ML55AMG 2000 SLK230/SLK320 2001-2004 CL500 2001-2003 CL55 AMG 2001-2002 A001 230 0211 80 S430 2002-2003 Mercedes-Benz S500 2002-2003 SS5AMG 2002-2003
  20. 20. E L E C T R O N I C DRIVER AIDS (Continued from page 17)few more components added to ESP to monitor Inputs,...Control Units,...the vehicle dynamics. The first one we will dis- Whats Next?cuss is the Steering Angle sensor. This is oftenmounted in the steering wheel switch housing. As mentioned earlier, no matter how compli-The ESP control unit uses this sensor to compare cated the system, its just a matter of monitoringto the front wheel speeds to verify traction is computer inputs, knowledge of computer opera-being maintained. It is a photo-electric sensor tion, and, finally, predicting and monitoring com-that generates a square wave. The shutter wheel puter-controlled outputs. We discussed how criti-that blocks and unblocks the light beam is in a cal CAN communication is, and checking forspecific pattern, so it is not an even and consis- codes in all related systems will help direct youtent square wave that you might be familiar with to the system at fault. For example, if there is afrom a camshaft position sensor, or something problem with the Electronic Accelerator, it willalong those lines. turn on the MIL and the ESP system will be What is more important is if you replace the disabled since it cannot shut the throttle when itsensor or battery power goes dead, you will have needs to. Its always a good idea to check all theto re-initialize the sensor. You can do this with control units in the powertrain CAN for codes.the aid of a factory-specific scan tool, or by When dealing with BAS/ASR/ESP, you need toslowly rotating the steering wheel lock-to-lock know that the computer controls solenoids towith the weight of the car on the tires and the redirect brake fluid pressure according to what isengine running. There is also a pressure switch desired. Mercedes-Benz uses Hold, Release andmounted in the hydraulic unit. It is a three-wire Pressure Apply solenoids in the hydraulic unit.sensor with a reference, signal and ground. The When dealing with codes, you are usuallysignal is an analog voltage. This sensor detects looking at a wiring problem, or sticking/faultybrake fluid pressure in the hydraulic unit. solenoids that are all incorporated into thePressure and return pumps in the hydraulic hydraulic unit. As well as using resistance checksunit create pressure that the ASR system may to test, we can also activate solenoids (preferablyneed to apply to a caliper. Remember, this is for through a scan tool) and monitor the currentcontrolling wheel speed under acceleration, relative to the voltage change.not braking. Other sensors found in the ESP system wouldbe just as at home in an aircraft as an automo-bile. They are the Lateral Acceleration Sensor Overviewand the Yaw Rate Sensor. The LateralAcceleration Sensor measures the speed of the We hope you have learned what input sensorschange in direction of the vehicle. It is a three- are involved in BAS/ASR/ESP. Checking forwire sensor and has a five-volt reference and a codes in all Engine CAN control units will giveground, as well as a signal wire. If this sensor you a diagnostic direction. Monitoring theseneeds to be replaced, it must be adapted with a inputs in scan data can help you quicklyfactory specific scan tool. The Yaw Rate Sensor determine what system you should be testing.detects the speed of body roll. This is difficult to After pulling up a wiring diagram, you can nowmonitor and is also best diagnosed with a facto- directly check sensor inputs and monitor ry-specific scan tool. A problem here could computer-controlled outputs that did notcause the SRS warning lamp to illuminate. You respond properly during scan tool testing. can monitor this signal wire for an analog voltage This all leads to the isolation and conclusion of a signal while driving the vehicle through turns. All successful diagnosis, no matter how complicated the system. We can all consider this a jobthese inputs go to the ESP control unit, so scan well done.data could make your life a lot easier.20 StarTuned
  21. 21. © 2007 Mercedes-Benz USA.LLC. A DaimlerChrysler CompanyRelive the good ol days. Mercedes-Benz makes it easier to find classic car parts.Call 866-MBCLASSIC, and Mercedes works to track down the Genuine Mercedes-BenzClassic Part you need. So you can be sure of one thing: they really do still makeem like they used to. Visit MBUSA.com/classic. Genuine Mercedes-Benz Parts
  22. 22. FEATURE ARTICLE / COLLISION REPAIR Mercedes-Benz has a long history with aluminum body parts starting with the famous 1954-1957 Gullwing Coupe. Beauty is Only Skin Deep: Working With Aluminum Panels22 StarTuned
  23. 23. HPfaoors and front and lilies of the new S-Glass areI maaeof aluminum. -The quest for reduced weight has led auto This historic vehicle either came with aluminummanufacturers to the use of aluminum, and hood, doors and trunk, or an all-aluminum outerMercedes-Benz has been in the forefront of this skin! An overall lighter vehicle improvestrend for decades. While these changes make performance, fuel economy, and reduces strainfor lighter body construction they also lead to on stressed components. Another benefit ofchallenges in auto body repair. Heres a look aluminum is how well it yields to manufacturingat the ups and downs of this miracle metal. processes. It can be cast, extruded, or rolled Some believe strict government regulations into sheets, the most popular use. While theseregarding raising fuel economy and safety standards benefits are tangible and real they do complicateforce manufacturers to change materials and the issue when accident damage occurs anddesigns. Others believe this is simply evolution body work becomes necessary. In order toof the breed. Whichever you believe, the use of maintain the Mercedes-Benz sound and stablealuminum body panels is becoming more and body structure and sufficient corrosion resist-more prevalent. ance, proper body work techniques need to be Mercedes-Benz is very familiar with the use of followed. Here we will review proper structuralaluminum body panels dating all the way back to the body repair techniques that Mercedes-Benzearly 1950s and the 300SL "Gullwing" coupe. owners require for their vehicles. StarTuned 23
  24. 24. COLLISION REPAIR/ALUMINUM PANELSAluminum and its characteristics The 2000, 6000 and 7000 alloys will strengthen with work hardening and some even with heat. Why Aluminum? Aluminum is roughly one They are also annealed with heat, but once againthird as dense as steel. However, in order to be careful of the lower melting points.maintain comparable strength to steel structures These characteristics become importantonly about a 40% weight reduction is acceptable. when heat is to be used in straightening theAluminum is also a great conductor of electricity, aluminum panel. The damaged portion of a paneland on vehicle bodies it doubles as a ground is stronger than the rest due to the work harden-path for the ever-increasing electronics on luxury ing of the metal. If you attempt to pull out thevehicles - it is one of the most cost-effective dent, the surrounding non-damaged areas will bechoices. Aluminum by itself, while being light- affected and warp. You should heat the damagedweight, is not sufficiently strong for automotive area to soften the metal and make it easier toapplications. While aluminum alloys often have work with. "Heat-shrinking" is a process thatsufficient tensile and yield strengths, an alloy uses heat to expand the aluminum around themust be formed to provide the necessary stiff- dent. If done properly, this should force theness strength. Aluminum alloys are made by metal back into the more natural shape it hadadding other metals and elements such as before the dent was created. Heat is also acopper, magnesium, manganese, silicone and recommended method for softening up bondingzinc. Different blends are used to create different adhesives used to join aluminum panels, butcharacteristics. For instance, a 2000 series more on this later. Of course, in more severealuminum alloy uses more copper. This makes hits heat shrinking will not be possible and thethe panel strong, workable and easier to stamp. panel will have to be replaced. Mercedes-BenzsA 3000 series alloy uses manganese and is still modular design of its vehicles allows dissimilarworkable, but also stronger. A 4000 series alloy metals to be bonded or riveted together to formhas a lower melting point, so it is mainly used for an overall stronger structure yet.welding. The 5000 series alloys are blended withmagnesium so they are corrosion resistant aswell as being stronger. In addition to inner andouter paneling, this alloy can also be used for Preparing forstructural components in the frame, as well as an aluminum repairwelding wire. A 6000 series alloy adds silicone tothe 5000 series so there is some additional During the aluminum panel stamping process,strength. Finally, the 7000 alloys add zinc, which water-soluble dry-type film lubricants andmakes the alloy strong and is primarily used in water-free dry-type film lubricants are used.structural members such as bumpers and While these protect the metal during forming,bumper reinforcements. they do need to be removed before any welding Aluminum alloys are basically split into two or painting takes place. Aluminum also has angroups, heat treatable and non-heat treatable. oxide layer on the surface that naturally forms aThe 3000, 4000 and 5000 series are non-heat corrosion-resistant surface. This must also betreatable. This means you cannot strengthen removed with solvents to allow for welding andthem with heat; however, they will harden by paint preparation.working them. If you need to, you can anneal Not only does the aluminum panel have to bethem with heat. Keep in mind, these alloys will clean, but your work area must be also. This isnot show signs of excessive temperature. one of the more critical steps in the process, but Heat reactive crayons should be used to give an it is often treated as the boring task left to theindication of how hot the metal gets as youre apprentice. While working on aluminum panels,annealing. Remember, the more heat cycles you steel contamination from the previous job, orput the metal through, the weaker it will become. from the job the next bay over, can cause paint24 StarTuned
  25. 25. to clean the panel before this occurs. Note: Cracks may also appear as pores, crows feet, a •_ « £»«•• •**• j or bulls eyes. ® Vehicle Body Information Working with the metal While aluminum is not as malleable as steel, dents may be removed from a panel when metal stressing is limited, or the actual disfiguration is minimal and not deep. Similar to steel, the tech- nician should take notice of the low and high points of the dent, then commence with repair. If :;. it is determined that the dent is too distressed, the panel should be replaced. Unlike steel, the technician should begin in the middle of the dentMBUSA offers a website for approved and work outward. As is done in "paintless" dentMercedes-Benz Certified Collision Repair Facilities. repair, the technician should "press" the dent outOn this site, you can access specific information by applying a small amount of pressure againston materials used by Mercedes-Benz and how the damaged area. It is required that wooden,they recommend that the material be secured. plastic or aluminum hammers be used should theproblems. Little dots protruding out of the paint need arise, and that any tools with sharp edgesare caused by the two dissimilar metals reacting. be avoided. Care should be given not toThere is nothing less profitable than having to do "stretch" the panel highly as that may cause it toa paint job all over again. For this reason it is crack or become brittle.required that your body technician keep all the Once the technician has determined that thetools dedicated to aluminum repair completely dent is relieved, it is time to "draw in" the alu-separate from those used for steel. Also a spe- minum. Before continuing, the technician shouldcial work area is required, which must be set off clean the surface of all contaminants.from the rest of the shop by either walls or floor- nit OPIKHIS iietpto-ceiling curtains. This will reduce the possibility untax 1 Lilemlun? | McOwi Cvrynreuls b annmnBej |«l¥YSl|of steel (or other material) contamination. ffc w&mM ^ w -4> *- 54 a # * Additional measures we can take to ensure * OSoparslrvqArrafar Document We Gr. ZEE 1 Dwurmrrti smj jri.jviittvnin J •C*wialnole6onrtirtfnflietNtQi*$inboijy!Wk 60.00 4ti6Q.D0-p-QU15-01nboth the health of the technician and the quality *• UHn:K»tnq tonri«liofi sorts en bedf * f j TV* NgfiMiliaria MfiftOtUttwHtfUflflWHHPi » HOHHtMtll Fiplnsinn hSTSrfl B JK J. U nfl Dfl am-!Ut> lIUUIHn afinnnn.?-nnnT^Ma i- C3 Piepawig rripi seiuun, HMMM Uri pwirlrjg 63.20 Bi6i:0-y-IIOO-D3nof the work is to provide proper safety attire and + n>jekirri|ininnerscag«ianJconsclc C ID 3 MBUP-p-HMMHn llllll lil III — , -t. nMeflrs wioair*«*kn! bUUUto remove contaminants and aluminum chips jlrMJfl-p-llOO-OSft Til* jweldino*!*with the use of a vacuum evacuation system. On: ru [we a^p-ltftWHnAluminum chips are explosive and pose a SCJ.IIM.L Stamensignificant heath hazard. Other steps include Outumenl | Picture I lewis I KirtJtcJ .covering the entire vehicle except the portionbeing worked on. Aluminum panels should beinspected for cracks before and after any repairsare performed. The surface can be inspected byusing color dyes that remain on the panel sur-face and will normally seek out "channels" that At www.startekinfo.com you can access recom-are created by cracking. Careful inspection mended body repair procedures. These include ashould be done after the dye is used as some list of recommended tools, step-by-step instruc-cracking may not be visible to the naked eye. tions, and required materials such as seam Never allow the dye to dry in the crack - be sure sealers, adhesives, etc. StarTuned 25
  26. 26. COLLISION REPAIR/ALUMINUM PANELSHeating the area with a "neutral" welding flamewhile staying within the 300 to 850 deg. F. range (using a heat crayon at the outer edges of therepair area will assist in maintaining the propertemperature), then allowing it to cool quickly willassist in drawing the panel in. Heating the panelwill allow the aluminum to resume its originalshape; however, it is important to keep the heatlimited to the repair area. This process should berepeated quickly and as needed to match thepanel characteristics properly. Re-sculpting the panels is a much biggerchallenge than it is with its steel counterparts.Unlike steel, aluminum panels need to be heatedbefore repairs can begin. The panel should bebrought to between 475 and 575 deg. F. andthen be worked by lightly hitting the panel witha plastic, wooden or aluminum hammer.Focus should remain on maintaining thesetemperatures during the repair to avoid the panel This weld was made with a new type ofbecoming "springy," deforming, or cracking. inverter welder. These welders use computersSince aluminum will tear quickly when the work to control pulsed current, in the thousands ofarea is crumpled or wadded, it is highly likely that cycles, allowing for precise control of current,the panel will need replacement rather than which keeps the high heat that can deformrepair. Do not attempt reshaping of any panels manageable.die-cast panels. Finally, always remember to do a post inspec- this procedure has its drawbacks. The heattion of repaired panel(s) for any cracking. required to weld aluminum can cause distortion just outside of the weld seam, particularly with thin sheets. Reducing current moves us closer toWelding aluminum "Short Circuiting Arc Transfer", which often leads to poor welds. Spray transfer is the preferred process when welding aluminum, but the Two possible methods of securing aluminum amperage required is still too high and causesbody parts are MIG welding and riveting. There distortion and fatigue. New welding technology isare pros and cons to both. To prepare the sur- available to address this need. Originally pulsedface for welding, solvents must first be used to arc welding could reduce overall current, yet stillremove any production lubricant as well as the maintain spray transfer. Today computers controloxide layer. Welding technology has evolved over inverter-based welders that can pulse a lot fasterthe past few decades to allow for more intricate and easily control overall current. Experienceddesigns in the manufacturing process. aluminum welders are hard to come by, so Manufacturers have moved away from resistance alternatives are needed.spot welding. Aluminum being a much betterconductor of electricity does not have enough resistance to build up the heat necessary to weld Rivetsthe parts together, so more current would be required. The other preferred method of mounting body Gas metal arc welding, MIG in particular, is panels is the rivet. Testing performed bya superior method for joining aluminum, but even Mercedes-Benz has resulted in riveted panels26 StarTuned
  27. 27. . . . on all eight with www.startekinfo.com.Mercedes-Benz USA Dealer Workshop Services is the source for all the technicalinformation needed to support, service, and maintain Mercedes Benz vehicles.Mercedes-Benz workshops rely on DWS products and services for getting jobsdone quickly and more efficiently. Our products include:• STAR Teklnfo with WIS-net (Workshop • Maintenance Manuals and Sheets Information System) • STAR Service Manual Library CDs• Electrical Troubleshooting Manuals • WIS and DAS software updates• Installation Instructions • Star Diagnosis System (SDS)• Technical Bulletins • Operators Manuals and COMAND Manuals• Campaigns • Mercedes-Benz Equipment• Mercedes-Benz Special Tools • Inventory of technical publicationsSTAR TeklnfoDealer Workshop Services Mercedes-BenzEngineering Services, Mercedes-Benz USA, LLC.
  28. 28. COLLISION REPAIR/ALUMINUM PANELSThis is a steel-to-steel application rivet.The serrations in the body help the rivet todeform in a specific pattern. This is a special Usibor rivet provided by Mercedes-Benz. These are intended for providing the same security and strength as in High-Strength steel applications.the vehicles original design. Mercedes-Benzactually prefers blind rivets over spot and plugwelds on certain models. Rivets eliminate the anti-corrosion coating is not scratched off.deformation caused by the heat of welding. Another tip to prevent corrosion is to eliminate How will you know when to apply this? moisture at the rivet point. Mercedes-Benz wantsAll this information is available with a paid a zinc paint, Part Number AOOO 986 34 42 to besubscription to www.startekinfo.com. This is applied to all naked metal surfaces before secur-the Mercedes-Benz service information website. ing panels. However, this "weld-through" primerUnder the heading WIS-net, you will find body is not recommended for MIG welding. Finally,repair information specific to your vehicle. seal the seam with a Mercedes-Benz-approvedWhen dealing with riveting aluminum panels uses seam sealer, and finish up with an approvedaluminum-bodied rivets to prevent dissimilar wax-based anti-corrosion compound.metals from reacting and promoting corrosion. Another component of rivet bonding is adhesives. Mercedes-Benz recommends the use Visit us at our website of adhesives between aluminum (and steel) www.MBWholesaleParts.com plates to reduce noise and increase strength. Remember to rivet in a different area rather than to view this article and all right where there was a plug or spot weld. The past issues of StarTuned, weld compromised the strength of the metal, so along with a wealth of information new metal will be more predictable and secure. on Genuine Mercedes-Benz Parts. Chamfer or deburr all drilled rivet holes on both sides of each panel to be joined to ensure the28 StarTuned
  29. 29. Enticingly graceful and dynamic. Strong support, too. ERVIC WARRANTY Every part comes with the reassurance of a strong 12-month/unUmited-mileage limited warranty with additional cumuge for engines and transmissions! Unlike anv other.The part is just part of the story. The precise fit and superior performance of a Genuine Mercedes-Benz Part 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 war Merrmles-BeiL: dealer for detaik and a a>py at the MercedesSenz Replacement farts United Warranty.
  30. 30. STARTUNEDFACTORY SERVICE BULLETINSEngine PerformanceComplaint from "False Air"Model 203.040/740 If you receive customer reports in the abovemodel of the engine vibrating, rpm fluctuations atidle or poor accelerator response with codes .£L «P2020 (P0172), P2046, P201C or P201A in theengine control unit, please perform the belowprocedure. The partial load breathing towardsintake manifold hose, cylinder crankcase breath-ing hose or the non-return valve to nozzle hosemay be torn at the connection to the crankcase.Air will bypass the air mass sensor, i.e. unmea-sured air will enter the intake, causing theengine to run lean.Remedy:1. Remove compressor (supercharger). Refer to WIS document AR09.50-P-4705QK. Figure 12. Remove and inspect the partial load breathing towards intake manifold hose, cylinder crankcase breathing hose and the non-return Note: valve to nozzle hose for crankcase ventilation. • Use "click clamp" as specified in parts If damaged, replace as needed. Refer to Figure information for securing hose. 1 for details. • Ensure that clamp is positioned as close to the end of the hose and fastened tightly.3.Install compressor (supercharger). Refer to WIS document AR09.50-P-4705QK. Parts Information Quantity Part Name Part Number 1 Click Clamp A005 997 49 90 As needed Partial Load Breathing Towards Intake Manifold Hose A271 018 12 82 As needed Cylinder Crankcase Breathing Hose A271 018 14 82 As needed Non-Return Valve to Nozzle Hose A271 018 15 8230 StarTuned
  31. 31. STARTUNEDGENUINE MERCEDES-BENZ PARTS... NEARBY Belmont Palo Alto Walnut CreekAlabama Park Avenue Motors Mercedes-Benz of Walnut Creek Autobahn Motors 650-637-2333 650-494-0311 925-937-1655DothanMike Schmitz Automotive Beverly Hills Pasadena West Covina334-794-6716 Mercedes-Benz of Beverly Hills Rusnak/Arcadia Penske Motorcars 310-659-2980 626-795-8004 626-859-1200HooverCrown Automobile Buena Park Pleasanton205-985-4200 House of Imports Mercedes-Benz of Pleasanton Colorado 714-562-1100 925-463-2525Huntsville Colorado SpringsMercedes-Benz of Huntsville Calabasas Riverside Mercedes-Benz of Colorado Springs256-837-5752 Mercedes-Benz of Calabasas Walters Auto Sales & Service, Inc. 719-575-7950 818-591-2377 951-688-3332Mobile DenverMcConnell Automotive Carlsbad Rooklin Murray Motor Imports251-476-4141 Hoehn Motors Von Housens Motors 303-759-3400 760-438-4454 916-630-8877MontgomeryJack Ingram Motors Chico Sacramento Littleton334-277-5700 Courtesy Motors Auto Center Mercedes-Benz of Sacramento Mercedes-Benz of Littleton 530-893-1300 916-924-8000 303-738-7700TuscaloosaLeigh Automotive El Dorado Hills San Diego Westminster205-556-111 Mercedes-Benz of Eldorado Hills Mercedes-Benz of San Diego Mercedes-Benz of Westminster 916-567-5100 858-279-7202 303-410-7800 Encino San FranciscoAnchorageMercedes-Benz of Anchorage Mercedes-Benz of Encino Mercedes-Benz of San Francisco Connecticut 818-788-0234 415-673-2000907-277-3383 San Jose Danbury EscondidoFairbanks Beshoff Motorcars Mercedes-Benz of Danbury Mercedes-Benz of EscondidoAuto Service Company 408-239-2300 203-778-6333907-456-6217 760-745-5000 Fremont San Jose Fairfield Fletcher Jones Motor Cars Smythe European Mercedes-Benz of Fairfield 510-623-1111 408-983-5200 203-368-6725ChandlerMercedes-Benz of Chandler Fresno San Luis Obispo Greenwich480-403-3400 Mercedes-Benz of Fresno Kimball Motor Mercedes-Benz of Greenwich 559-438-0300 805-543-5752 203-869-2850PeoriaMercedes-Benz of Arrowhead Glendale San Rafael Hartford623-583-7200 Calstar Motors R.A.B. Motors New Country Motor Cars 818-246-1800 415-454-0582Phoenix 860-278-2000Phoenix Motor Laguna Niguel Santa Barbara602-264-4791 Santa Barbara Auto Group New London Mercedes-Benz of Laguna Niguel 805-682-2000 Carriage House of New LondonPhoenix 949-347-3700 860-447-3361Schumacher European LaJolla Santa Clarita480-991-1155 Heinz Gietz Autohaus Mercedes-Benz of Valencia North Haven 858-454-7137 661-753-5555 Mercedes-Benz of North HavenTucson 203-239-1313Mercedes-Benz of Tucson Los Angeles Santa Monica520-886-1311 Downtown L.A. Motors W.I. Simonson Delaware 213-748-8951 310-526-4700Arkansas Santa Rosa Milford Manhattan Beach Carwell Smothers European I.G. BurtonFayetteville 302-424-3042Mercedes-Benz of Northwest Arkansas 310-303-3500 707-542-4810479-521-7281 Modesto Signal Hill Wilmington Modesto European Mercedes-Benz of Long Beach Mercedes-Benz of WilmingtonLittle Rock 209-522-8100 562-988-8300 302-995-2211Riverside 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 Oakland Coral GablesArcadia Torrance Bill Ussery MotorsRusnak/Arcadia Mercedes-Benz of Oakland Mercedes-Benz of South Bay 305-445-8593626-447-1117 510-832-6030 310-534-3333Bakersfield Palm Springs Van Nuys Daytona BeachMercedes-Benz of Bakersfield Mercedes-Benz of Palm Springs Keyes European Mercedes-Benz of Daytona Beach661-836-3737 760-328-6525 818-461-3900 386-274-4775 StarTuned 3 I

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