We bought a 2002 CLK430 convertible earlier this year. On several occasions, one or more of the windows have gone all the way down by themselves when the car is turned off. It's a little disconcerting to park the car, lock it, and find the windows down when coming back to the car! Sometimes, it's just one rear window, sometimes it's all the windows. The most recent time it was all but the driver's window, which is how it is now, in the garage, thankfully.

Also, on several occasions, the trunk lid has unlocked by itself, always while we are driving. We took the car to the closest MB dealer (200 miles from here) last month, but they did not fix it. We're taking it to an independent shop here in town next week. They are good, and undoubtedly less expensive than the dealer, but they are not MB specialists.

From what I've read, a short in the wiring or a bad ground might be the problem.

Any ideas to share with the shop?

Thank you.

Check the wiring harness near the emergency trunk release button. I've seen them rub through on the deck lid sheet metal. Once the inner trunk liner is removed it's pretty easy to see.

Thanks for the suggestion. I'll take a look a look and will also let the shop know when the car is there next week. I was hoping that the mechanic at the dealership would be able to diagnose the problem, but I guess he couldn't. The repair order said "completed scan had no issues with any control units...could have a issue with the aam control unit but not certain at this time."

We took the car to a local shop. They could not see a problem with the wiring harness, and concluded that the window and trunk problem was because of a faulty "ACC module" or "body module." I assume this is what the dealership referred to as the "aam control unit." The shop said a dealer would have to install a new one and program it. They also said it might be possible for the dealer to reprogram the existing module. How does this sound? It sounds expensive to me!

Well, the shop didn't see anything wrong with the wiring, but I decided to take a look myself. When I took the liner off the trunk lid, I found a wire from the emergency release button was dented where it contacted the sharp edge of the trunk lid, right where the wires were tightly fastened to the lid with a zip tie. I cut the tie and put some electrical tape on the damaged wire, and we haven't had a problem in 3 days. I sure hope it's fixed now. Thanks for the advice. I found a post on BenzWorld describing the same thing, and one of the replies said there was a TSB on this. I guess the MB dealer didn't get that one...