Hey guys,

I picked up a black on black 94 SL600 a couple of weeks ago and have been going around in circles trying to get it on the road. When I purchased the car, I was informed by the previous owner that it would not start/run, and that he had been told by a shop that the passenger side throttle body needed to be replaced. I enjoy wrenching on cars as a hobby, and thought this might be a fun project (the previous owner also practically paid me to take the car ). After getting the vehicle home and off the trailer, I checked all of the fluids, charged the battery, and she started right up! Unfortunately, the ASR and check engine lights were illuminated on the dash. After doing a bit of research I ran across the following website detailing the rebuild of the electronic throttle actuators on the M120:

http://v12uberalles.com/throttle_actuator_rewire.htm

I spent the week ordering supplies, and the following weekend rebuilding the harness on the passenger side actuator. After re-installing the re-wired actuator, and following the reset process outlined in the how to, there was no change in the function of the car. Currently the symptoms are as follows:

-ASR light on at all times (regardless of whether the car is hot, cold, or started with the brake pedal depressed)

-Car has absolutely no power.

-When the car is driven and reaches about 4k rpm, it either up-shifts in an extremely rough manner (jolts the entire car), or bounces on an imaginary rev limiter @around 4k rpm and then makes the rough upshift.

I’ve plugged my Snap-On MT2500 and the appropriate cartridge (Mercedes through 01), personality keys, and cable into the 38 pin connector, and came up with quite a bit of information. I’ve put all of this information into .pdf format and then attached screenshots of the .pdfs to this post.





I don’t have a lot of experience with Mercedes electrical systems, but after a quick scan of the data pulled with the MT2500, the following things pop out to me:

-The ignition voltage for the DI1 side of the engine reads a fairly consistent 29.1 volts. The ignition voltage for the DI2 side of the engine reads a consistent 0.0 volts. This says to me that the engine is running on six cylinders.

-The manifold air pressure difference, ignition angle, and intake air temp seem to vary from side to side.

-There is a large difference in O2S voltage, canister purge duty cycle %, and hot wire air mass from side to side.

-The vehicle speed shows to be 190mph while the car is parked and idling.

-The LH-SFI Ref Resistance is wrong

-There doesn’t seem to be any communication from the Electronic Actuators, Cruise Control, Idle Speed Control, or ASR.

I’ve attached several pics of the new car after a good wash. Any suggestions from those of you with technical expertise in the R129 V12 arena will be greatly appreciated.













Thanks in advance,
Craig Rhyne