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Discussion Starter #1
Hey everyone, i have a 1999 Mercedes ml320 and at first had a problem where it would drive fine until a certain gear change and then it felt like it slipped. It would shift but only after slipping atleast once around 3rd or sometimes 4th gear. Eventually after a longer drive the car would slip more often and then end up going into limp mode. First thing i did was change the tranny fluid and filter because the oil seemed a bit dark and very slight burn smell. Did not fix the problem though. I do and always make sure to have enough fluid in it. We then replaced the conduter plate and connector harness thinking this might be it and sure enough there was some issues. The harness had oil leaked into it so we cleaned it out and added a new one then we put in a new conductor plate. The old plate was cracked at the sensor part of it. We assumed these two things were the issues that caused the problem. We put it all back together again correctly, filled oil but now the car drives only in 1st gear. Still works in reverse but not higher gears. No telling if it still slips because it now wont upshift at all...whole new problems it seems. Almost like the car forgot how to shift..very rarly when i first put it from park to drive it does nothing. Does not switch gear at all and i press gas it revs but car does not move. But as i said very rarly for the most part it shifts fine from park, reverse, and drive. Just issue is it stays only in that first gear...goes on slow speed and high RPMs so its undrivable now...Any idea what could be causing this? Recently replaced other parts of car as well and tested things such as transmission control module, throttle position sensor, a new kickdown, and cleaned the mass airflow sensor..so far nothing. Connecting harness seems ok and dry still so belive it to be ok but cant be sure. Even thought i bought a faulty new conductor plate so got a different one to double check..ran my code reader so see what codes would recently pop up and i got the ones below in the image. The speed sensor code is gone now however but the solenoid a, b, c, and torque codes are all still present..plz help, i miss my car.
 

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E320/E250 Bluetec Ford F350 6.7l
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You should learn that pilot bushing on those transmissions is pretty critical part and should be replaced at EACH transmission service, or every few years.
Now did you check for transmission fluid migration inside TCU ?
Than you let the car slip into permanent limp and now only SD scanner can clear it.
It is 2nd gear btw.
 

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Purple Moderator
99 ML430, 00 ML320, 05 E500 4matic Wagon
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Once repaired the transmission fault codes must be cleared in the ECM and the TCM or it will stay in limp mode.
 

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Discussion Starter #4
I had a mechanic friend help me with all the work so felt pretty confident. But we did clear the codes with a scanner. It was a basic scanner tho and seemed to clear the codes as it should. But car then still stayed in that gear and eventually codes would pop up again after a little drive. Do i need to try with a more expensive reader? Ill have to look at the pilot bushings tho but not sure where those are located.
 

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1999 ML320
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You need to find someone with a xentry laptop that has hht-win on it (a windows x86 install). A xentry install on an x64 windows system does not have hht-win (this being a 16 bit app). That car, that year, it's done in hht-win. Call some indy shops in the area and ask them if they have what I mentioned above. DO NOT GO TO THE STEALERSHIP!!!
 

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Discussion Starter #7
Well we got access to a special mercedes benz computer scanner and we deleted the codes and rest the whole thing. Still same issues tho...but my thoughts now are since i put a new conductor plate in, do i need to reprogram the car? I heard that a new plate wont respond with the TCM since its not the original plate...do i have to take it somewhere to be reprogrammed so that the plate and TCM and function again or should it be ok? Also about the TCM itself could be an issue too, feel like it too may have been messed up and require it to be repaired or get a new one..which in that case im sure the car woyld definitely have to be reprogrammed correct? I know alot of questions but just tryingnhard to figure this out. But overall thinking nee TCM and reprogram the car is what i need to do at this point.
 

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E320/E250 Bluetec Ford F350 6.7l
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You jumped into conductor replacement, but no indication about pilot bushing replacement?
Beside wet plugs on the transmission, it is also well known that ATF likes to travel along wire harness and flood TCU. Lot of members restored it all with $20 worth for new bushing and can of MAF cleaner.
 

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Purple Moderator
99 ML430, 00 ML320, 05 E500 4matic Wagon
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Also once the plate once replaced were the codes cleared from the ECM and TCM? They have to be cleared from both.
 
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