ML320 Conductor plate changed, CEL still on- Gilly???

[Nailgirl]

Hi folks! I have about gone blind reading on this forum. Here is my story-

2001 ML320 bought used from a dealer with 96,500 miles on it. When test drove, car worked great. (I previously had a money pit 02 ML320, so I knew what to look for... I thought... but I digress...)

Had a problem with the battery dying. Never had to jump it, but I figured the car had sat for awhile on the lot. Dealer paid for us to get a new battery, we installed it, did all the steps. Problem fixed. I thought.

A few weeks later, when accelerating from a stoplight, car goes into limp home mode. I was right down the street from home, so I drove it home. Next day, started and drove just fine. It did this a few times, and restarting the car made it reset fine. Then, it would go into limp home mode and the CEL would come on... but again, restarting cured. It did this for about another week. Finally, the CEL light came on, it went into limp home mode, and restarting didn't fix. Damn.

I parked the car for about a month. During this time, I lost all the power steering fluid due to a leak in a hose, so it was no longer driveable to limp to my mechanic. So it sat for another month. I had it towed to my indy mechanics shop... where he fixed the power steering thing with a new hose and fluid, but the codes for the CEL were P0715 and some other code for an engine misfire. The car runs fine (with a slight engine skip, but I figured from past experience that it needs new plugs and wires... maybe coil packs.) but still in limp home mode and CEL on. My mechanic had a tranny shop look at it for a second opinion, and they agreed it needed a transmission replacement.
I refuse to believe that a luxury car with less than 100k needs a totally new tranny so I started my research. I found that we could replace the conductor plate for $250 plus labor and misc parts/supplies, so I asked my mechanic to do this. After I showed him all the research I had done, he agreed.

He replaced the plate, "cleared" the code. CEL still on, still in limp home mode.

He sent to his friends tranny shop. They took it all back apart to verify he did everything right (he did) and attempted to clear the codes with 2 super-wamperdine code readers. CEL still on, still in limp home mode. Still P0715 code.

Called the local dealer. They said to bring it in, and for $125 an hour, they will try to figure out what it wrong with it. They said that the P0715 code was useless to them, it is a generic code and there could be other things wrong to give that code other than the conductor plate. This is the same dealer who, by the way, insisted that I have my cylinders pulled for my last cars misfires... that only needed new plugs/wires/coil packs, so I don't have a lot of faith in them.

This is ridiculous... do I need to ask a shop if they have a specific code reader to clear the code? What else could it be that is giving the code? The tranny shop said everything inside looked fine... a little worn, but fine. I have read Gilly's posts extensively, and I am sure that some of you guys on here can help me.
Please help me! Broke at christmas and need my car!!! By the way, bought the car in June and have barely been able to put 1,000 miles on it!!
I love these ML's, but dang!!! Please advise, oh knowing ones... My mechanic is interested too!
Michelle Cordes in Washington

[engatwork]

Hi folks! I have about gone blind reading on this forum.

You sposed to do that on that other forum. Just kidding, welcome aboard.

You got to get someone with a Mercedes Benz SDS "super-wamperdine" code reader to tell exactly what is going on. May have to find another independent mechanic to get it.

[mbdoc]

Ditto!

You need to have the code(s) read & cleared from the TRANSMISSION computer as well.
The code P0 715 is an engine code that points to a trans issue and means to read trans codes.

[ILUVMILS]

A shop equipped with an SDS, and someone who actually knows how to use it to diagnose transmission issues is what you need. Also, I don't see any mention of checking the transmission ECU for fluid contamination. This is one of the first/simplest things that should have been done.

Find a competent, properly equipped shop and stop wasting time and money on expensive guesses.

[Nailgirl]

It was checked for contamination before we swapped out the conductor plate and it was fine... And as far as the fluid....dark fluid, little bits of metal. Nothing big. And I just held the old plate in my hands yesterday... it was pretty worn compared to the new one...

I have found a local shop that specializes in Mercedes and BMW, and prides themselves on being the less expensive dealer alternative... and is close enough to drive to in limp home I'm calling later today... any other advice on what I should ask them?

Thanks for the input already guys, I appreciate it....

[engatwork]

Let us know what kind of codes they get out of the transmission.

[ILUVMILS]

Originally Posted by Nailgirl

... any other advice on what I should ask them?....

Yes! Assuming they have an SDS, they should check the transmission adaptation data. This is the best way to determine the condition of the shift members without tearing the transmission down. Let us know what happens.

[Gilly]

Hi, I just read through this, haven't been watching the ML forum like I used to. All makes sense to me, if it wasn't the conductor plate or connector not sure where to go now except what has been recommended. Could possibly be the fluid-in-the-ETC problem as noted, or maybe the shifter, you haven't dribbled into the shift gate have ya?
Shouldn't take SDS to get the ETC code, but probably going to take more than what autozone uses.