bobrich53

2001 C200K transmission locked in limp mode, code shows fault with solenoid. Solenoid tested ok but still replaced and unable to clear fault code. Board also tested OK. Any suggestions anyone.

Ausmbtech

What was the fault code you found?
Have you checked the oil level?

bobrich53

I thank you so much for your interest. Code shows as 4102. Oil check OK. Transmission specialist changed solenoid but same code and will not clear. Tested old solenoid and board and both OK. Powered down transmission and all solenoids showed up as fault. Powered back up and all cleared except this one. I have posted a thread with the problems I have had. In brief - battery leaked and ate through battery tray and two looms, replaced looms and fault codes then showed MAF and cam sensor faults, both replaced. Car ran OK for 2 weeks and then locked in gear on freeway. Went into limp mode after stopping and then diagnoised as broken vaccum line to aux vac pump and replaced this but unable to clear code for gearbox. This is now where I am. I consider that I have had very bad luck but cannot recall any mirriors, black cats or ladders. Love the car to bits but now gone beyond expense. Transmission specialist ( Merc send their problems to him) and mechanic stumped.

408vette

Check for oil in the harness to the computer and in the computer itself.

bobrich53

Thanks for the suggestion but the harness to the computer was replaced and computer checked for oil, negative. Just seems to be a hard code in the computer that will not clear.

Ausmbtech

4102 isn't a usual benz code, what description do you have of the code?

The 2 usual colprets of a soleoid code are a faulty ECU or a damaged electrical plate in the transmission. It's very rare for the soleoid to fail.
Some low milage vehicles have pressure problems cause by a faulty valvebody, seeing yours is an older vehilce it's unlikely to have occured without prior shift problems.

TMAllison

Isn't the trans harness part of the overall engine harness?

Why was it replaced? Was oil contamination present?

bobrich53

Reply to Ausmbtech. Sorry, correct code is P0745 Pressure Control Solenoid Malfunction They tried a new one but same problem, they tell me they tested the 'plate' but it was OK.

Reply to TMAllison All replaced due to battery acid eating through the lot. See above for the sad tale. By the way, I have a friend who is into geanealogy, Allison is in his family, originates in Stranraer, Scotland.

Ausmbtech

Seeing you have a new control unit I would say you have an internal leakage or wear in the valvebody. Pretty common to get the wear in the valvebody, unusual not to have had a prior shift problem. I would find somewhere that can rebuild AND bench test the valvebody in house or get an exchange unit.

vettdvr

This is what I was thinking. The pressure control might not be defective but actually low. So the next step would be why is the pressure low and this could be valve body or other internal issues.

I haven't worked on MB tranny but I have been working for the last 3 weeks on a rebuild hd diesel transmission with similar issues. It looks like mine is going to be the PCM.

bobrich53

Thanks gents, latest place tried replacement TCM but still same problem, actually got it working but on test drive went back to locked 2nd gear. They are currently pulling out valve body for inspection and testing. What should I be paying for a replacement or rebuilt body?

bobrich53

Dear all, apologies for the silence I have been waiting on reports re the problem. Latest is that all previous work has been checked and everything OK, Transmission pulled to pieces, all checked and all OK. Final result is ---Computer thinks transmission is a manual and not automatic and will not clear code. Any suggestions anyone. I have now been without the car for 5 weeks. They now tell me if the code cannot be cleared, new computer. Bit drastic, cant they be rebooted of something.

vettdvr

I went through on my diesel truck with similar issues.

1) All the wiring must be correct. NO guessing here. I actually did a point to point check on all my wires.

2) If the wiring is correct. It was on my truck. The PCM (computer) is now suspected. I finally convinced the transmission shop to replace the PCM and that solved my issues. The PCM actually controls all those parts you changed out. If it doesn't function correctly you will go to a failsafe condition which you have.

You mentioned that the PCM was thinking you had manual vs. auto.

1. How do you know this?
2. Was it auto before?
3. Why did it change from auto to man?
4. If it is working and does think it is manual why can't it be reprogrammed.

It is possible the acid damage on the wire harness failed the pcm and this results in it acting as manual. It could be just damaged.

I spend $5000 on my truck to finally get it right and the PCM change solved it. The down side was I had to read the entire electrical manual on auto/electrically controlled transmissions to sort it out.

If you can get a PCM I would change it out. WARNING it must match the antitheft system and be matched to your VIN # or the car alarm system probably won't let it start after installing a new PCM.

loubapache

The P0745 is s generic OBD II code. There are underlining DTCs in the EGS causing the generic P0745. Clearing the P0745 does not clear the DTC in the ETC. These codes have to be cleared for the ETC to power the solenoids again. Does the repair facility have special equipment that can reset Mercedes transmission EGS DTCs?

alpman

hey i have a similar problem on a w203 c180 2001. The gear is stuck in either one or two and cant get up even when i rev into red mark. a night before the gear was shifting with a noise and sometimes the car wouldnt just pick up speed from rest on time. there were times when i would rev up but the car couldnt move until after a few attempts. This time its locked in 1 or 2 and the mech came and checked the gear box oil level. The low was found to be low and then i topped it up. Tested it and problem never went any where. what next and what could be the problem.