Archive for the ‘Mercedes’ Category

Mercedes SL600 with wiring problems   3 comments

We are working on a very clean and original 1995 SL600 (129 chassis) that has less than 30,000 miles on it. Unfortunately this vehicle was made by Mercedes with faulty wiring insulation that has deteriorated and caused short circuits in many components.  The main engine harness (just includes the fuel injector wires and a few others) is in the worst condition. The main body mounted engine harness has some wiring circuits that are bad, Mostly the air mass meter harness. This harness is over$5000 for the part and approximately 60 hours labor to replace. It runs from the headlights to the trunk of the car, behind the dash and under the interior. This job at the Mercedes dealer could legitimately be $14,500. Just for the body mounted harness. Here at Autobahn Performance Inc. in Ft. Lauderdale Florida we have developed a repair kit and procedure to repair this harness without removal for less than $1800. It will work on V12 engine in the 129 (SL convertible) chassis and the 140 chassis (4-door sedan or 2- door coupe). In rare cases more than the normal wire circuits are affected by the insulation deterioration and the harness is unrepairable. This is usually only in European-delivered vehicles and the sedan 140 chassis. If a wire suffers from insulation deterioration the entire length of wire must be replaced. Trying to splice onto a section of the wire will not work properly and will result in short circuits and possibly a fire. The insulation will start to crumble near where you are trying to repair it and you will probably make your problems worse rather than better.

The throttle actuators (electronic controlled throttle body, TBA Throttle Body actuators): There is one for each side of the engine. (note: the one on the right side of the engine feeds the air into the left side of the engine and vise versa) The actuators have a short wire harness coming out of them, it’s about 14 inches long, that connects to the body-mounted engine harness. These harnesses also have the insulation failure problem. The harnesses are part of the actuators and are not available as a separate piece from Mercedes. The Actuators can be rebuilt and new harnesses soldered into place. Again, do not try to repair these as you will not be able to properly connect new wires to the electrical connector end of the harness. Short circuits in the wiring of the actuators commonly cause damage to the E-GAS actuators (the control units that control the throttle actuators). These also can be rebuilt.

Wire insulation failure on Sl600 injection harness

we carefully cut a slit in the throttle actuator harness to inspect the wiring, In this case the wiring is shorted together and the vehicle should not be driven until repaired

a pair of Mercedes throttle actuators that were removed for rebuilding 000 141 5525 and 000 141 5625


Posted June 29, 2011 by jayauto in Mercedes

Tagged with ,

Mercedes-Benz will not sell valve body for Mercedes 722.9 transmission   35 comments

Update 9/6/2013
We are able to get the 722.9 conductor plates and valve bodies for our customers. They take a few days to get and we have to provide the correct documentation but we are able to get the parts for most local customers. (The dealrs do not even stock these so it takes a few days if you bring your vehicle to the dealer) We have had issues with private dealer owned vehicles that have open titles. There is currently now way to get a TRP part if the vehicle is not owned and registered by an individual. 2013-01-31 16.33.40

Mercedes now will not sell 722.9 valve bodies or conductor plate control units, even with the TRP paperwork completed. The newer Mercedes 7-speed transmissions (also called G-tronic) have the electronic control unit mounted inside the transmission these control units are failing frequently; with speed sensor codes (the usual codes are related to speed sensor faults). The speed sensors are not replaceable as they are part of the electrical conductor plate that bolts to the valve body inside the bottom of the transmission. The transmission does not need to be removed to replace the valve body or the conductor plate. A valve body does come complete with the conductor plate / control unit. Early valve bodies must be replaced as a complete unit but later second or third generation units can be repaired by just replacing the conductor plate / control unit assembly. We have replaced many of these and have the capability of performing the SCN coding to complete the installation of this repair.


complete valve body with conductor plate


electrical conductor plate with control unit, solenoids, speed sensors

These units are failing so often that the dealer has restricted selling them even in their own shop. To order a part the dealer must submit a request with computer scans and control unit log reports of the suspected failed vehicles electronics. The factory then sends the parts they deem necessary for the repair (conductor plate assembly or complete valvebody).

It’s rumored that Siemens VDO the manufacturer of the electrical control units is in a battle with Mercedes over the validity of failing units. Why should an
internal problem with Mercedes and its suppliers affect our ability to acquire parts and repair our customer’s vehicle? Mercedes is requiring the vehicles be
brought into one of their dealers for any valve body or conductor plate repair even if the vehicle is not covered under warranty and the customer is paying for
it. In our customers view this would be perceived as an inability for us to repair their vehicle and give the dealers an unfair advantage at gaining the
customers business. One customer lost for life could be worth hundreds of thousands of dollars.


Visit for more info

Mercedes TRP Theft Relevant Parts   1 comment

Mercedes TRP       Theft Relevant Parts 

Mercedes-Benz USA has recently (effective date November 10, 2008) tightened the reins on their sales of theft relevant parts. At Autobahn Performance Inc. we are trying to work with our local dealers and with other affiliates to work through if not around this problem. As it stands now if we are repairing a vehicle with a part that is classified under the theft relevant parts policy as a TRP part, the vehicle must be brought to the Mercedes dealer and the part must be installed there. Theft relevant parts as I understand it at this time include;

[1] Keys electronic and traditional blade type (also green and orange programing keys)

[2] Electronic Ignition Switch EZL

[3] Infrared Control Unit , Drive Authorization Module DAS,

[4] Locks and Lock Cylinders mechanical and electronic

[5] Electronic Selector / Shift Lever Modules (electronic shifter assembly) on models 215, 220 and 230 only

[6] Transmission gear control unit (Electronic Valve Body on 722.9 G-tronic transmissions only

[7] Engine Control Module

[8] Flashware or repair Cd’s (software programing updates) 

[9] Certain Airbag / SRS Supplemental Restraint System cables etc.

[10] Body Shell, certain body panels and components

These descriptions of parts listed by Mercedes are very vague and could include parts associated with a substantial number of the repairs we preform at Autobahn Performance Inc. We have the equipment and the capability of installing these parts as long as they remain available to us.


It is insulting that Mercedes and our local Mercedes dealers that we purchase parts from do not trust us or think that we are stealing vehicles or parts. If the dealers correctly fill out the paperwork and forms on the theft relevant parts we purchase there would be an obvious paper trail leading back to us, if a vehicle we had repaired was reported stolen. There is no way, for any amount of money, Autobahn Performance Inc. would knowingly become involved in the theft of a vehicle and jeopardize our reputation and name for the minimal profit of selling stolen vehicles or parts. Our annual sales averages are in the millions of dollars without the aid of stolen vehicles or parts.

Some of the parts listed seem to have no relevance to the possibility of using the part to steal a vehicle. How could you steal a vehicle with an ignition lock cylinder (with no key to it), or with an unprogramed engine control unit (ME control unit). The only way that I can see is it you use that part to throw through and smash the glass window of a locked vehicle to gain access to the interior of that vehicle. I hope Mercedes is not trying to corner their share of the repair market by requiring customers to have their vehicle repaired at the dealer. This would be a monopoly and should be illegal. The dealerships seem to be using the TRP policy to therir advantage by selectively enforcing their interpritation of the policy and requireing that vehicle be brought to them to be repaired when the ssale of parts is refused due to the policys vague guidelines.

From what I understand the reason Mercedes is pressing this issue is to keep insurance costs on their vehicles down. If the vehicle is harder to steal or is stolen at much lower percentage rates, the customers insurance cost to insure that vehicle will be lower. In turn Mercedes should sell more cars due to a lower cost of ownership.


At Autobahn Performance Inc. we are in the process of becoming a Licensed locksmith. With this We will be able to purchase keys and lock cylinders. It is an expensive and drawn out process and might take some time before we complete this process. 


If anyone has any further information or updates on this policy please contact me. I would like to hear your stories and ideas on this subject.

link to Mercedes TRP policy

link to Mercedes November 7, 2008  parts ordering announcement
Theft-Relevant Part (TRP) Form with Documentation Checklist of Theft-Relevant Parts
Visit our website that has a page dedicated to this issue for updates and changers

Posted April 16, 2009 by jayauto in Mercedes

Repair Information Seminar / Class for Mercedes   Leave a comment

For half of the day on Friday and for most of the weekend, Malte Dau, Lucas Cerotti and Jason Athanas of Autobahn Performance Inc. attended a repair information seminar. Over 90 hours of total committed time! The seminar was presented by Marty Vellozzi of LMV Industries. It was a very informative class that was attended by many Mercedes specialty shops from around the state of Florida (and other states). Surprisingly, none of our local northeast Broward competitors was present   The Seminar’s main topics were diagnosing and repairing problems on modern Mercedes vehicles including: the onboard communication bus system (various C.A.N. systems); understanding and properly reading electronic troubleshooting diagrams and repair manuals; and other recent repair issues. It was great to interact and learn from the instructor and the other shops that attended (our competition).
Jason has been attending the LMV seminar yearly for over 5 years; two times were in New Orleans when the seminar was not offered in this state. Malte has attended the seminar several times and has always benefitted from the experience. It was Lucas’ first experience with the class and he was impressed. Lucas has considerable training through Mercedes at their training facilities in Texas and Jacksonville. He said that this class was much better at actually indicating areas of common problems and what it took to find and correct the problems.  He mentioned that in contrast, the factory instructors just seemed to pump out a bunch of information with no interaction with the students. 
Autobahn Performance Inc’s philosophy has always been to repair a customer’s vehicle in the fastest way possible and with the least number of parts. This keeps the repair cost down and the customer happy and returning for regular service and maintenance. This seminar will help us diagnose and repair a vehicle quicker and with more accuracy. The investment in this seminar with three technitians demonstrates Autobahn’s commitment to training and education that will save our customers money and aggravation and keep them returning to Autobahn Performance Inc. far into the future. 
Autobahn would like to thank Marty, Reiner Whittich, and Bob Beckman for organizing and creating the seminar and the support systems that keep us informed and up to date with the latest technology, information, parts, equipment, and tools that keep us on the leading edge of automotive service and repair. With their help we are far superior to dealership service and repair and are equipped to handle repairs well into the future.    

Posted March 15, 2009 by jayauto in Mercedes, Our shop