RoyaZrcv

Hi all folks.

I would appreciate some help if someone has faced the same issue or knows why it is caused. The car is a 2007 ML500 5.5 V8 388hp.

Basically the brake lights are constantly on while driving or backing up no matter the speed or if headlights are on.

To be more precise I have noticed the following behaviour:

1. When I am driving in "D" or backing up in "R" no matter if I am pressing the brake pedal or not - the brake lights a constantly on.
2. If I am driving and then I stop and put it in park or neutral the brake lights remain on UNLESS I open the door. As soon as I open the door (in P or N) the brake lights turn off.
3. If I have my door open and the car in P or N pressing and releasing the brake pedal - the brake light function properly.

I would appreciate any advice. Thanks

UPDATE: Today I tested driving with door open - brake lights work correctly. As soon as I close the door while driving brake lights stay on constantly until I open the door again.

RoyaZrcv

Just an update for anyone who might come across this thread with the same issue even tho no one responded. The problem was the rear SAM module. It was replaced and the issue went away. A bit more info - it was replaced with a SAM from a pre-facelift R-Class so no coding was needed.

happy 2023

BlackML550

Its no surprise that you didnt get a response as it sounds like the first time that specific issue has arisen - I assume you serached it up and there was notning similar, altougj rear SAM issues are everywhere. Is good that you posted the solution for others.