722.6 transmission codes (C230, 98)
 

My Tech reported transmission codes on my C230, which has had the trans opened 3 times by MB before it reached 50k miles (each time for 2nd gear slipping on accel, sometimes slipping in other gears as well. Sometimes it would suddenly rev to redline while driving at a steady speed.). Each time they redid some of the things they had done, and did additional 'factory part upgrades', and used new factory trans fluid - described on a previous thread . At 50 k, the trans was better, but still slipped when downshifting into 2nd occasionally (like when coasting up to a light, then accelerating when it turned green before I came to a stop).

The trans has had 1 or 2 codes read by my Indy tech at each service ever since MB finished with it. This time there are four:

104 revers/park solenoid defective
118 R/R wheel speed signal from traction system
119 R/L wheel speed signal from traction system
135 CAN: Communication fault with engine system

My tech doesn't do trans work - can someone explain what the codes mean in more detail, and the implications for the trans? I believe MB Doc said the failure of the trans parts may have set up the trans for early replacement. Is this likely to be what is starting, or are the codes relatively benign? if replacement is the case, is having the old one rebuilt the way to go, or is it better to go with a newer factory unit?

Thanks for any input.

error codes
 

they codes are obvious--the ASR/ABS system is getting faulty data from the left and right rear wheels, and the computer is saying it is the Car Area Network causing the problem. Can be 'bad wiring', a loose connection,low battery voltage, a bad ground, faulty ABS computer, etc.

It will take some good diagnostic work to trace it down. Don't be lured into replacing expensive parts until all the connections (including all the ground points on the car) are checked and verified as sound. 99+% of these kinds of problems are faulty connections--due to the connector itself, (or failed wiring insulationon MBZ )

Thanks for the input - I will run it by my tech. The battery was changed out 6 months ago, and the wheel codes have been seen before and after the change out, so maybe low bat voltage can be ruled out? The darn car still slips on 2nd gear shifts every 4 or 5 days, though, so something isn't correct with the trans, IMHO. I have never before had a car with an auto that occasionally takes 2-3 seconds of racing engine sounds without much acceleration going on while shifting down into 2nd.

John,

Something is wrong. It just is not right in there somehow. The adaptation values for the tranmission would be the first place to start, looking at each shift. But, after that, tracking it down is probably going to mean getting arm-pit deep into the case.

You have a serious case for going back to MB-USA, as if my memory is correct, this began when the car was well within warranty, and the dealer fumbled the ball on correcting it. You may get nowhere, but you won't know until you become a bit of a squeaky wheel.

Good luck!