Trunk issue (s)?
https://www.edmunds.com/mercedes-ben...gned-trunk-lid
it’s also very common for the trunk buttons to not work, that’s because the wiring from inside the trunk to the trunk lid is encase in a retractable coil that gets severed. The coil is located where the trunk cable goes from the lid into the trunk. So that’s the problem why your trunk buttons inside and outside the trunk are not working.
Also, for the reason why the corner of the trunk is not closing properly, you likely have a combination of 3 problems - weak gas trunk struts , low fluid in the hyraulic trunk lifter , bad pse pump for the trunk latch . Do the first two and see if that fixes it . The gas struts are simple to access and cheap on eBay or Amazon . The hydraulic trunk lifter is encased in foam under the battery and you can add ATF in its fluid reservoir
Last edited by tusabes; Mar 31, 2024 at 10:54 PM.


For the high corner: Use a good penetrating oil, such as Kroil (but not WD-40) on every joint in the trunk hinges every day for two or three days.
For the non-functional PSE operations, look behind the right rear passenger's heels and find the floor lamp. Pull it out of the carpeted wall, but don't bother to disconnect it. Find the yellow 20-Amp fuse toward the right end of the row, pull it out and see if it is blown. Replace it, reinstall the lamp, and see if the trunk functions now work. You have just reset the PSE (Pneumatic Service Equipment) Control Module.
For the possible broken wire, look in the forward right corner of the trunk, and find the cloth-covered wire harness running from the body to the trunk lid. That harness winds out and back on a spring-powered drum as the lid moves. It is common for a wire or two to break due to the flexing.
Hey guys, there is plenty of fluid in the pump. I checked the wiring and didnt see any severed wires. I dont really know what i am looking for though. Im not sure what the next step would be. any help appreciated
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IF the problem is a broken wire in the trunk harness, there will not be a severed wire. There will be a wire buried inside a wire harness that has broken inside the insulation, but still looks perfect.
IF this is the problem, repairing it will not be fun, but will be a real learning experience.
IF this is the problem, your choices appear to be:
- Learn to do the repair yourself. Hours of research, hours of fiddley work. Virtually no cost, and a great feeling of satisfaction after you successfully do the repair.
- Pay someone else hundreds and hundreds of dollars to do the repair.
- Live with it.
Look carefully at the third photo. On the top edge, above the yellow wire, you will see what looks like a black U-shape plastic piece. Inside that piece is a cloth-covered wire harness. That is the harness for the wires on the trunk lid, and is the harness that winds in and out on a spring-loaded spool. It is not unusual for one of the several wires inside that harness to fail from metal fatigue due to years of flexing. That may not be your problem in this case!
One approach is to find where the wires disappear into the harness near the spring-loaded reel. Pick out a wire using the color code of the wire. Go to the wires in the first photo and find the same color code - the same wire. Use two fine straight pins and a multimeter to check for continuity on the wire. If/when you find the broken wire, you get to take the harness and reel out of the car, dig down into the harness and find the broken spot, and repair it
Again, check everything else first, starting with resetting the PSE Control Module, then checking for a failed pneumatic actuator.
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