W212 W212 Gear Selection Problem( the gear automatically shifts to P from N, R or D)

[nic3939]

I have a mercedes benz e250 cdi 4matic which calls w212 and whose model year is 2012. I have a problem with the gear selection which is that the car automatically (by itself) shifts to P from N, R or D while moving at 0 to 8 km/h or not moving. Firstly, I went to a mercedes authorized service, and they checked the car and they updated the gear selector and they said that it is okay, but the problem continued.
1)It has no fail code so it shows that everything works properly.
2) Generally, after the car goes 20 kilometers(11 miles) or higher, i stop the car and then again start and then the problem is existed. In other words, when i start the engine again the problem is existing.
3) The gear shift to p from N,R or D three or four times. For example, I shift to D or R or N but the gear automatically shift to Park then again i shift to D or R or N but again the gear automatically shift to Park Then, the gear is not automatically pass to Park. Therefore the car works perfectly after making the shifting to p three or four times.
After that, i went to another mercedes authorized service, serviceman says that the problem can arises from left door lock or ignition. It makes sense, because when the key is removed or the left door is opened, gear shifts to P.
My observations and experince are that when the gear shift to P, it has no warning like door is open or the top light is open. I use my spare key but the problem has not been solved.
thanks a lot for your help. Sorry for long writing.

 

[st13phil]

After that, i went to another mercedes authorized service, serviceman says that the problem can arises from left door lock or ignition.

As I read your post I was going to suggest a door sensor, as the car will automatically shift to Park at very low speed if it detects a door open. I think that's where I'd be looking.

 

[PhilLinda]

@st13phil beat me to it. That would be exactly my verdict too. Can't see why else the car would shift to P.

 

[Petrol Pete]

I have a mercedes benz e250 cdi 4matic which calls w212 and whose model year is 2012. I have a problem with the gear selection which is that the car automatically (by itself) shifts to P from N, R or D while moving at 0 to 8 km/h or not moving. Firstly, I went to a mercedes authorized service, and they checked the car and they updated the gear selector and they said that it is okay, but the problem continued.
1)It has no fail code so it shows that everything works properly.
2) Generally, after the car goes 20 kilometers(11 miles) or higher, i stop the car and then again start and then the problem is existed. In other words, when i start the engine again the problem is existing.
3) The gear shift to p from N,R or D three or four times. For example, I shift to D or R or N but the gear automatically shift to Park then again i shift to D or R or N but again the gear automatically shift to Park Then, the gear is not automatically pass to Park. Therefore the car works perfectly after making the shifting to p three or four times.
After that, i went to another mercedes authorized service, serviceman says that the problem can arises from left door lock or ignition. It makes sense, because when the key is removed or the left door is opened, gear shifts to P.
My observations and experince are that when the gear shift to P, it has no warning like door is open or the top light is open. I use my spare key but the problem has not been solved.
thanks a lot for your help. Sorry for long writing.

Don't apologise for writing a long post, the more detail you give the more chance people on here can help. We see many posts asking for help when they don't even give the smallest of detail about the car or fault. Welcome and good luck

 

[Justintyme]

This may or not be what you are speaking about Nic3939, but next time it happens ( assuming that the problem has not been fixed already ) check if there are other cars parked along side.....In my 212, the "P" shows if I am driving slowly ( under 20kph ) down a street, with cars parked on either side... it's looking for a parking space.
Speaking of which, while I know why this is happens with my car..., it's a far cry from Automatic parking, where the vehicle actually parks itself, so how does it actually work???? Does it only tell you via the sensors that the space is big enough to park in? or does it assist in some way?

 

[richard]

That big P Justintyme is talking about is auto-parking. When it is on, the car will reverse park itself (you do accelerator, it does steering). I've only bothered once ever with that so can't remember how it works, but it is documented in the manual !!

nic3939 - Great Description.

a) There is an 'Emergency P' function on some (maybe all) Mercedes W212 auto gearboxes. It happens on low voltage (so is your battery failing?) or if communication with the servo module fails (i'd expect the latter to log a fault though). The extra battery (the small one) is used to operate the solenoid.

b) As others have said, opening the driver's door (in your case the left) will select P at slow speeds, and if its a very short open signal you may not see the light coming on etc

Hope that helps

R

 

[Justintyme]

That big P Justintyme is talking about is auto-parking. When it is on, the car will reverse park itself (you do accelerator, it does steering). I've only bothered once ever with that so can't remember how it works, but it is documented in the manual !!

nic3939 - Great Description.

a) There is an 'Emergency P' function on some (maybe all) Mercedes W212 auto gearboxes. It happens on low voltage (so is your battery failing?) or if communication with the servo module fails (i'd expect the latter to log a fault though). The extra battery (the small one) is used to operate the solenoid.

b) As others have said, opening the driver's door (in your case the left) will select P at slow speeds, and if its a very short open signal you may not see the light coming on etc

Hope that helps

R

Mine is a 2010 w212 E200 CDI Blue Tec Auto Richard. Will it do the steering itself as well on this model?
Thanks Justin.

 

[moog999]

No. It will bring up a steering wheel icon in the display that tells you when and how much to turn. On the 2 times I tried it was happily driving me into a brick wall so I don't tend to bother with it now.

To be fair I probably wasn't using it in a textbook condition, maybe it works better than I give it credit for, not sure.

 

[nic3939]

Hello everybody,
I am very late to give information about my problem.
The problem is solved. So how? The ignition processor was changed and now it works properly.
Thanks everybody.