okbarnett

Trunk lid doesnt close fully, will not do automatic lock down position.
But after manually working with the lock mechanism it started working again. Then worked 5 or so times and stopped. I had to pull the pse pump fuse and reinsert it to reset the fault.
it will work 5 or 6 times then quit again.
It is also making a prolonged vacuum sound at the lock after it clamps down. Maybe 5 to 7 sec. I dont think it was doing this before.
Has anybody had trouble with the trunk lock or pse pump ??

TheWorkshopMB

trunk lid not closeing /possible pse pump problem? If you are hearing a vacuum noise at the trunk latch area, then the vacuum port has came apart. This is common on CL's, you will need a new trunk lid latch assembly.

Contact you local dealer or give us a call at 800 992 3694. If your a preatty good DIY you can install it yourself, otherwise if you are located in the SF/Oakland area, swing by the shop and we can install it for you. As well as anyother service/performance items you might need or want.

Happy Benzing!!

okbarnett

Thanks for your response.
I fixed this problem yesterday, and didnt cost anything. I asked MB and 2 other shops about this and all answered the vacuum noise indicated a leak in the vac system parts in the latch assembly. All said to replace it. ( one unit, $375)
I took everything apart to see exactly what was leaking. I finally found a split in one of the plastic tubes that pipes the vacuum to different places in the mechanism. It was in a spot I could coat the split with epoxy and seal the whole little tube.
So this elimated the leak and cured the problem.
If you do have a vacuum sound around the latch mechanism, or the auto lock down wont function, and a trunk lid not closed warning, this is most likely caused by the lock mechanism. You can completely replace it, or dissamble it and look it over good and try to find the source of the air leaking. If you happen to have a bad part, the 3 vacuum canisters and electrical switch are available seperately and have good 220 part #s on them.

IngenereAMG

Mine is not closing, but I don't have vacuum noises. You mentioned the fuse. Where is the fuse for this?

Thanks.

okbarnett

behind pass seat, in storage comp. take out false bottom. its 20a fuse.

If all your other vac mechanisms are working it should be the latch assembly that is bad. Youll have to diagnosis it. Make sure there is vacuum getting to it on the yellow tube.
There is 2 electrical switches in it and 3 vac modules and lots of mechanical arms and moving parts.

JBFMCAR

I'm experiencing your exact problem with the trunk closing right down to pulling the 20 amp fuse and making it work. Now my question is where do i find these hoses you speak up to check for leaks are the located on the trunk lid under the carpet? Let me know want to get to the bottom of this.

Justin

NikleinR6

Check out my post here..
https://mbworld.org/forums/sl-class-...w-fix-diy.html

-Nick

mdotpoker

I had this same issue.
I took it to my local independant on Monday and he replaced the pump.
The CSC warranty saved the day again.
If you have warranty i would just have the pump replaced.