Nubbian

The automatic trunk opening/closing started malfunctioning strangely and I cannot seem to figure out what is causing it. When I open the trunk (no matter if it's done via the handle on the trunk, the button inside the car, or the button on the keyfob), the trunk starts to open, but the trunk doesn't open all the way. It stops every time in a different position - sometimes it stops shortly after starting to open, and sometimes it goes half way. If I press the button to open it again, it opens fully without a problem. The same is when I try to close it - it starts closing, but it stops closing once reaching 70-80%. When the close button is pressed again - it closes perfectly. I have checked and the limiting height is not turned on, so that is not the problem. Every once in a while it opens and closes without a problem. All other features (soft close) work perfectly. My guess is that it doesn't seem to remember its position because if it were a motor failure it wouldn't be able to open and close the 2nd time the button is pressed. I believe a simple reset could do the job, but I do not know how to do it. I would appreciate if any of you could share some tips before bringing it in to the dealer.

konigstiger

Needs to be checked by dealer or independent with Xentry (MB diagnostics) 'may' be drive unit - erase any stored codes, pull new codes, reset if need be, and check for software updates.

Jac0bkaan

I had same issue when I bought car one morning didn’t closed 23 times at 5am , bring to service they sad everything ok then next week one morning did same again and I searched only and found somewhere says lock not working propery some cold weather conditions, i share them with my mechanic and got same answer old locks has plastic parts in side and after while they worn but tey updated locks with metal inside similar issues on gmc and other automatic trunk locks too he sad , we replaced lock and problem solved now

konigstiger

MB EPC is not showing part has been superseded.

acpmc

Had this problem a few months ago, they reset the software and it was fixed. Good luck.

WLB

I am experiencing something kind of similar in that the trunk pops open but will not go up or down and has to be done manually. When done so it latches fine. The other issue is the two interior trunk lights and the two red buttons on the lid are not illuminated.