I took it to a mercedes benz specialist and they said it could be a door actuator.
Mercedes a class rear door lock problem.
What you need to do is to apply a small amount of tape to the door lock pin.
This issue is a failure of the internal door lock actuator which is failed in the lock position which is causing the door not to open.
This was done on a 2004 mercedes c230 kompressor sport coupe.
The issue of the mercedes door lock actuator bouncing up and down affects the w203 c class and.
Bert rowe s mercedes benz a class info.
The actuator will have to be replaced which will require the door panel to be removed and with the door closed this won t be easy and needs to be done by a garage or dealer that has done this before.
The circumstances were uncannily alike both owners had purchased used a class both had only owned them for a few weeks.
Earlier this year the driver s door would occasionally not open unless i pressed the key fob repeatedly.
Ensure the door pin can go up and down.
Take your mercedes benz for a test drive.
Your door lock should not bounce up and down anymore.
Remove the door pin or at least pull it up in the unlock position.
The way that this fix works is by creating resistance at the door lock pin.
Our local mechanic couldn t identify a problem.
Take 1 inch of electrical tape and apply it around the door lock pin.
And the door lock problem turned out to be an identical problem in that the internal locking button cable had broken at the lock end leaving an s shaped length of the cable rod a see below which prevented the vacuum locking mechanism from working.
Check your fuse box first to determine if a blown fuse is keeping the lock from working.
If key fob is working you may have a faulty key fob which can be repaired or replaced by taking it to your dealer.