Mercedes-Benz Forum banner

Door/Trunk locks just stopped working - Vacuum?

6146 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 - 6 of 13 Posts
Vacuum pump is located in the trunk, on the right side, to the outside of the battery. If memory serves, it is behind the fabric trim, and encased in a block of foam.
Thanks. So, since the trunk release is vacuum operated, how do I get into the trunk in order to replace it?
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.
Uh oh... I've tried that, but it doesn't work. I can turn the key in the trunk and even make all the windows open, but I can't actually get the trunk to open.

Any other ideas or am in a really bad spot now?
Thank you so much!! That did the trick! I was turning the key all the way to the left, but instead just turning it a 1/4 of the way to the left opened it no problem. Very much appreciated! Now, I can start trying to diagnose this vacuum problem.
Well, it's fixed! Being able to get into the trunk changed everything... it was a single burnt out fuse in the trunk.

Thanks again for taking the time to help me!
  • Like
Reactions: 1
Much appreciated. Thank you!
1 - 6 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.