Sun roof opens of its own accord during night

Help. My 1997 C180 sun roof opens during the night by about 10mm of its own accord. Also it Sometimes it opens when I press the remote unlock remote control key. I;ve had the motor replaced and the switch with no joy. Any suggestions.

[dpetryk]

Find an excorcist.

[mbdoc]

The 1994 & later C-class(US models) use a computer to operate the sunroof & it is powered-up all of the time part number is 202-820-09-26.
The only time this should operate the sunroof is when locking doors(or unlocking) OR if you operate the switch.

[JimSmith]

I think the problem lies with the keyless entry control circuit. The motor will not start without getting electricity and none of the position switches or the dash operating switch are energized when the car is shut off so they cannot do anything to energize the motor.

The car's electrically operated mechanisms may have some kind of position switches that tell the control system that you access with your remote key the status of items like the windows and the roof so when you ask the system to shut the roof and windows when it locks the vehicle it "knows" what to do. I think the tilting sunroof does have some limit switches to sense position, which could either be out of adjustment (telling the system it is not in the proper position when you lock the car) or the system could be influenced by interference. There could be electromagnetic interference from some adjacent source, or, since I believe these things work with an infrared signals as well, you could be getting interference from some other infrared controlled item in your home, like a tv or stereo remote, or possibly a neighbor's stereo remote.

I would not suspect the motor or the dashboard control switch as they need some other help to support clandestine operations. If you are locking the car from a distance with the remote feature on the key maybe the sunroof moves at that time and you do not see it from where you are standing?

You should move the car to another place and see if it continues to happen. Fixing these systems can be costly and frustrating. Good Luck, Jim

[280CEBoy]

Stray infrared signals hitting the door recievers?....maybe just enough to whack the sun-roof module? Does it happen every night?

Re this sunroof problem. since the replacement of the motor, the roof is only opening up when the car is locked. Is this an indication that the roof is out of sinc.

my car doesnt even have that bad of an attitude..

that is wild as ever.

by chance did they try to ground it on the back of the sunroof fuse?

good luck

benzat 1982 380 SEC