Jumping into park

[benm]

Hi, I have a 2013 w212 with a rather frustrating problem. The car occasionally jumps into park when the speed drops below 10mph, i.e. when coming to a halt at junctions and in stop/start traffic.

Drive can always be immediately selected without turning off the ignition and in all other respects the car is operating correctly. No problems locking/unlocking or starting.

I believe that forcing the car into park at low speed is an anti theft measure if an invalid key is detected? It happens with both the keys I have and no faults are stored. When testing the Drive Authorisation using my scanner all seems as normal.

Any ideas what is causing this issue? I don't think it is a bad key as it happens when using either one. Is it likely an EZS electronic ignition problem and does anyone know if this can be tested/repaired? Alternatively can the "anti theft" forcing park be disabled?

Thanks

Ben.

 

[SpikyMikey]

Maybe a dodgy door switch? If MBs are like BMW, if the car detects operation of the courtesy light switch whilst in motion, it will select park. I believe this action is speed limited to avoid transmission damage.

 

[benm]

I've not been aware of the interior light coming on but will check for sure next time it happens.
Opening the door whilst stationary in Drive causes the transmission to go into Neutral then immediately into Park. The problem I experience jumps straight from Drive into Park with the accompanying unpleasant noise of the parking pawls grating.

 

[benm]

Took EZS out to inspect for damage. All looked OK but there were some hairs floating about. Cleaned it up and reinstalled. Has been fine for the last few weeks. Fingers crossed