brewtoo

Watch my W212 2012 E350 shift itself into Park while still in motion. Also, note bottom line of scanner where system is intermittently unable to see the key. 70K miles. Same behavior with both keys. Doors are closed. Does this look like a safety issue to you?

I don’t seem to be able to post the video. Sorry.

chassis

Welcome! Please post a photo of the E350. How long have you owned the vehicle, what is the service history, and how long has this phenomenon been occurring? Are there any modifications to the vehicle of any kind whatsoever? Dash cam, radar detector, audio system, aftermarket LED lighting?

If you are driving at 60mph / 100kmh and the transmission shifts into park, I would begin considering whether or not it was a safety issue.

Please provide alot more information. This lets others help you.

LILBENZ230

Shifting to park while in motion sounds like an ISM issue. Have you had a chance to get it hooked up to a Mercedes specific scanner?

brewtoo

https://www.dropbox.com/s/sw29mvcpt2...%20PM.mov?dl=0

MBENZTECH

It's your EIS (Electronic Ignition Switch). It's a common issue with some W212's. You will need the latest part number available for your car. But I am going to let you know right now, the EIS is only sold at Mercedes dealerships or license independent shops. If you were in Houston Texas we can get you a new part from dealer as we have all the proper licensing to purchase these parts.

brewtoo

Thanks for your kind response. According to the documents I’ve read, the problem is an assembly issue that involves defective adhesive and the height of a chip above the diodes where the key is sensed. Can this not be repaired rather than replaced?

MBENZTECH

If you can find someone that can..... I just replace it.

Chevota

If it were me I'd open that puppy up and try to fix it myself. After all, if the normal fix is to replace it then I guess you can't make it worse. I'd also take pix for others so if you fix it, or make it worse, it'll be helpful for the next person(s).

I'm sure the aforementioned answer is the right one but I wanted to add that mine does that if the door is ajar AND the door moves in/out. By ajar I mean it's on the first click of the latch but not fully closed. Drove me nuts at first because I only use the first latch a lot but it rarely trips the park thing. I finally realized the door moving in and back out is what does it.
So I mention it as a remote possibility that the door switch can apparently do it too, like if it was bad and randomly opened the circuit.

brewtoo

Thanks. I did open it up but did not notice anything obviously wrong. Nor was I able to spot the defective adhesive and the chip sitting at the wrong height above the diodes, as mentioned in Mercedes documentation I have found describing the problem.

LILBENZ230

Trust @MBENZTECH - if he says EIS, then that's your problem. What's the cost of replacement? $1200ish if I'm recalling correctly what I've read in the past?

brewtoo

I agree the EIS is the problem. Just wondering if it’s possible to repair it rather than replace it. Mercedes knew there was a problem with these components. They got it right a few months after my car was built. I disagree, but they seem to think cars shifting themselves into park while in motion on the streets is a no big deal, based on the fact that they chose not repair the affected automobiles.
Quite frankly, I would rather not help MB profit twice off their mistake, once when I bought my car and once again if I have it replaced.

Chevota

I'd still be trying real hard to fix the existing part, or bypass it. There is a way of course, the trick is finding it. I wish there were more and better info on parts like that, like an electrical schematic. I don't even know what the module looks like, and certainly not the insides. Like that chip near the diodes, not sure what that's about but based on that limited info I guess I'd move said chip even closer? Or maybe get the # off the chip and buy a new one?
Would it be safe to assume it's intermittent? Meaning if were just broke then I'd imagine you'd never get out of park, so apparently it works for bit then fails? If so then maybe it's temp related? Often poor solder joints will show up with temp changes, or a chip internally will have similar issues. So a solder fix for the first and a heat sink and/or cooler for the latter?
If you open it up again please post pix. If you buy a new one please ask for the old back and again pix...
LILBENZ230: You mentioned a MB specific scanner. Do you have a suggestion? I looked at Autel but waaay too confusing as to what model does what or if they're of any use at all. So outside of spending $35K for the official Star system, what can us normal people get that's worth it?

brewtoo

I

I use this scanner.

MBENZTECH

You don't have to get a new one, but I would recommend you to get the latest part number available for your VIN. In order to buy a new EIS from the dealer an indie needs special licensing and in order to install a used one an Indie needs special hardware/software. I can do the job with either a new one or used one, but I am in Texas. If you PM me your VIN, I can take a look and see what part numbers are available for your car.

juanmor40

@brewtoo did you get this problem sorted out?