E Klasse Central Locking Problems

That sounds frustrating. I had a similar issue with my E Klasse. Same symptoms: central locking went haywire, car locks wouldn't respond. I'd start by checking the fuses related to the central locking system. It's a simple thing, but often overlooked. Did you check the wiring loom where it passes from the body into the door? Those wires can fatigue and break over time, causing intermittent or complete failures like you're seeing.

I did check the fuses; all seem fine. The wiring loom is a good shout. I'll have to investigate that further. Is it a pain to get to? Do you have to remove the door panel to properly inspect it? Or is there an easier way to get a visual on the cables? I was hoping for a quick fix but it sounds like the locking mechanism cable connection is the culprit.

Accessing that wiring loom can be a bit fiddly. You'll likely need to partially remove the door panel to get a good look. It’s not rocket science, but take your time and be careful not to break any plastic clips. Honestly, given the error code you're getting and the symptoms, it might be best to have a workshop take a look. They'll have the proper tools and diagnostic equipment to pinpoint the exact issue, and they can repair the wiring properly if needed. It will save you time and frustration.

Thanks. I think you're right. I was hoping to avoid it, but I'm going to take it to a workshop. I'd rather have it done right than mess something up worse myself. I just got it back from the shop and it was indeed a faulty cable connection as suspected. 95€ later and the central locking and car alarm are working perfectly again. Thanks again!