I have an intermittent problem with the trunk lid popping open on my 1999 CLK 430. Started when the cold weather hit in December and happened at the same time as my PSE pump burned out disabling power locks, power trunk release, headlamp washers and headrest-down functions. I replaced the PSE pump and everything works again, but the trunk lid still occasionally pops open, and I'm worried that my PSE pump will fail again due to burn-out. You can't hear it running unless you actuate one of the functions, but there must be something. Any ideas out there?

 

the microswith inside the trunk lid handle is malfunction which causes this problem.
you have to replace the whole unit. a modified version is available. make sure you got a newer part number than the existing one.

 

I know this is an older post, but I bought a 2002 C320 last summer, and the trunk lid just started popping open this past weekend. I've been able to lock it with the valet key so it doesn't open automatically. But that is not the solution, just a temporary fix.

Could you specify what you mean by the "whole unit" you mention here? Is this different from the PSE pump mentioned in the other post? I ask because the same night my trunk started popping, the rear passenger light began turning on by itself. I was driving a four hour trip and became very annoyed because the light kept coming on, like every 5 minutes.

Anyway, any insight will be helpful and appreciated.

 

he means the whole trunk latch assembly