First off, I'd like to say I have searched the forums for help but could not get any info that is similar to my issue. Many trunk stuck issues.

I have a 2002 C240 and my trunk stopped opening. It will not open with the remote, will not open after you unlock the car and pull the outside trunk handle, and it will not open if you hit the button on the driver side door. It does open using the blade key. I have checked the fuses and they are all fine.

This problem started when my fuel pump went out. I don't know if one triggered the other or if its just coincidence in their timing. The fuel pump is fixed and working fine but the trunk release is still non-operational.

I have taken out my lining in my trunk so I can see the parts that operate the trunk release. I don't think this car uses any air power to operate the trunk. I didn't see anything like vacuum hoses or air pumps (as referenced by other posts).

It appears that the trunk release has two parts. The part with the release handle and blade key socket and the part that catches the loop at the bottom of the trunk to lock (both electrical). I have a hunch that the motor inside the part that catches the loop is non-operational. I could hear it sometimes when the release handle was pulled (it won't unlock even when the motor turns on) but sometimes it does not come on. Today I cannot hear it after the first pull. I don't know if its programmed to not come on after so many pulls or if this is a sign of failing.

Does anyone know how to test this part (the one that catches the loop at the bottom) or have had this happen before and can confirm that this part is bad? I would hate to go buy a part on a hunch and to find out it was not the cause.

Also, has anyone had this happen and can chime in with some advice? Any suspicion that may point to the unit with the handle and blade key socket?

Any help would be greatly appreciated. Especially if it means saving some money from being lost to the dealership for diagnosing.