Mercedes-Benz Forum banner

Door/Trunk locks just stopped working - Vacuum?

6145 Views 12 Replies 4 Participants Last post by  LukeHill
Hi everyone,

I have a 1999 c280. Out of the blue, all of my door locks and my trunk release have stopped working. I'm assuming this is the vacuum pump?

If so, can anyone tell me where it's located so I can replace it? I haven't been able to find the information online.

I have seen a few posts that suggested it might be in the trunk. If so, how would I access it, as without vacuum, I can't get the trunk to open (even with the key).

Thanks in advance.
1 - 3 of 13 Posts
Just push the trunk lock, it doubles as a manual way to open the trunk! If the trunk isn't unlocked, you will have to unlock it with the key.
Does the vacuum pump run when the central locking is activated? I believe the fuse for the vacuum pump is actually in the engine compartment fuse box (which would make way more sense than having it in the trunk, like for example when your situation happens!). Check the fuse, it's possible it blew for some reason, there might still be something wrong, but maybe with a new fuse it would at least allow you to open the trunk and continue diagnosing further.
And keep that lock lubricated! Mine is already seized, tried to spary in some oil but it didn't help. I'm in for a surprise if my vacuum system fails. I was thinking of going to the dealership soon to get a new lock put in the trunk specifically before something like this happens :D Glad to hear it worked out, I also had no idea you could stop the trunk from opening like that, it's pretty cool!
  • Like
Reactions: 1
1 - 3 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.