Hi all... My W210 E420 tranny went into limp home mode on my way to visit family for the thanksgiving holiday. With the help of DIY's and reading dozens of experiences of fellow forum members, I was able to trace the problem to the transmission electrics plate from the p0715 and p0720 error codes.

I picked up most of the parts needed, including an authentic mercedes replacement plate at a great price, through carquest (same day order/pickup). Swapping it out wasn't that difficult at all, and as the weekend wore on and I waited for dealers/indy shops to reopen after the holiday this morning (to clear the limp home mode and codes) I felt ever more confident that the problem was solved. The car is driving wonderfully now.

But unfortunately, I found brass or copper shavings upon breaking open my transmission filter. (See attached photos.) I have no idea if they are fresh or if they've been there awhile, and regardless, am worried about what it could mean and if there is any additional service that should be performed imminently before anything gets worse.

I took the filter and shavings by two different indy shops and both kind of had a "drive it a bit and see if you notice any problems" attitude. I don't think one shop digs too far into transmissions and the other does but they don't sound cheap. I guess I'm inclined to agree (depending on what I hear from y'all), perhaps for a few thousand miles, or maybe more, to see how this repair of the electrics plate feels and if I notice any other issues.

Anyway, I wanted to post photos of my shavings to see if I could get some opinions here on the forum and so that the pics and those opinions would be available to those researching similar problems in the future. Please let me know what you think about this! Thanks in advance.

 

out of limp. drives fine. all fluid replaced,drained torque converter?
If so drive it. If that was the first fluid change wear particles are just part of normal wear and partly the reason to change fluid.

 

Thanks so much OhLord. Glad to hear they seem like normal wear and tear. I think this may have been the first service, or the first service in many thousands of miles. The tab was broken off the dipstick tube. There was a funny shaped bit of metal in the pan that caused me a great deal of concern until I realized that it was a magnet, and it seems like something that could have been left in from a previous service. (I'm hoping that there are not other places in the tranny where this chip of magnet may have come from.)

On the torque converter, I got stumped on how to turn and access the drain so I ended up skipping it this time around. I know it can't be drained on later models anyway, so thought that might be OK, especially as my main goal was to get to the root of the limp home mode and any issues causing it.

Plus, I want to crack the pan open again in 3 to 6 months to check for any new shavings, and I want to put a magnet in since I didn't have one on hand for this repair. The magnet that was in the pan didn't seem very helpful and it made me nervous just sitting at the bottom. I'd rather crack it open again and put in the mercedes magnet.

 

I just wanted to follow up and say that the car has still been running fine, and once again the folks on these forums were a lifesaver!

Also wanted to add a reminder that pretty much goes without saying... be careful not to strip out the many screws, especially on the valve body, if you are getting into this conductor plate replacement. Use a high quality torx screwdriver, and think about adding one of these screws to your parts list before getting into the repair just to be safe. These screws can be really tight and I was barely able to salvage one after getting it out. I would have preferred to replace it but there was nowhere for me to go get a replacement on a holiday weekend. I read in other threads that a few people have also faced similar trouble with the screws.