Phillyfinest

Very weird thing happened to me last nite. I was out watching the football games last nite and at a friends house.

I was leaving to go home at around 11pm. The temp outside was about 26 degrees. I put some things in the trunk and closed the trunk. The trunk would not stay closed. Every time i closed it, it would go all the way down, and the pop back open.

to get it to stay closed, i had to close the trunk and hold it down with 1 hand and lock it manually with the mechanical key in the other hand.

drove home and went to bed. Got up this morning and went into the garage and used the key fob to open the trunk. It opened. Then i used the key fob to close the trunk, and it closed. Seems like its back to normal.

don’t know what its problem was last nite. Will keep an eye on it in case its the beginning to something going out.

just thought I’d share with everyone.

hope everyone is staying safe and healthy!

as.thompson

Cold temperature causing the locking latch to contract enough so it wouldn't latch completely?

Phillyfinest

Good question. I;m not really sure why it was doing that. But it did stay closed when I used my mechanical key. And it is working fine right now. May have been the temperature. Even though that should not matter, but with the electronics ion these cars, who knows.........

Jud Chapin

Did you happen to wash the car earlier? Ice can cause such problems.

Phillyfinest

no I didn’t but it was cold and the car was covered with frost so maybe that was it.

hyperion667

Mech could have been frozen; we've been getting SO much damn rain on the east coast!

Mitch Alsup

I had a similar failure:: after driving 6 hours in a whiteout at about 22ºF I stopped at a car wash to wash off the 1" thich ice sheet on the front and sides of the car. I saw my rain coat with about 2 SQ inches hanging out of the trunk. So I opened the trunk and it would not close. I drove home the next day with the trunk not closing (another 9 hours) mostly just above freezing. After a night above freezing the trunk would still not stay closed, so I took it the MB. Once the tech hooked up the scanner, the trunk would close !!

One would think a car designed in Germany would be better in freezing conditions.

MBNUT1

You would think.

604benz

I had a similar issue with trunk not closing last year, i googled it and someone suggested pressing the flashing green button inside of the trunk lid, it seemed to reset the lock for me and i have not had that issue since.
Hope it helps if you have issue again

salamigs

There is an open campaign for this apparently. I had no issues with mine, but they changed the assembly for me. The only reason I was OK with that was because I did not want to end up in the boonies with the lid not latching, and not being able to workaround it either somehow. The campaign number is 2019030005. Here is the link;
FILE: (carmd.com)
The inspection text is funny; it is looking for an orange dot on the lock assembly (mine did not have it, it has it now since May). In the failure condition, the lid would not latch/lock, and open back up, and you have to reset it with the green button on the inside.
The OP's condition seems to be a bit different, and more cold weather/ice related, but I thought I should share...

rnpalmer

same thing happened to me on a cold night in Florida on my 2018 S560. After a restart everything returned to normal and hasn't happened again since (over a year ago).

fun33

Same problem with our 2018 S560. Started occasionally not locking and they became progressively more frequent. Dealer replaced trunk lock under warranty - possibly a limited recall. No problems since lock was replaced.