Peugeot 806 electrical errors

I had similar issues with my 806. It started with the radio cutting out and eventually escalated to random warning lights. Have you checked the wiring harness near the passenger footwell? It's a common spot for corrosion and damage. A faulty connection there can cause all sorts of electrical gremlins. Is it always the same group of systems that fail?

Interesting, I hadn't thought to check specifically the passenger footwell. When you say "similar issues", did you get the same range of symptoms as me? The audio/nav stuff is definitely the worst, and most frequent, but sometimes it's other seemingly unrelated systems. Was that the same for you? And, if so, did that passenger footwell fix resolve it for you then?

Yes, the symptoms sound very familiar. It did start with audio/nav, but branched out over time into other seemingly unrelated systems. While cleaning and securing the connection at the location didn't fully resolve the root issue for me, it did stop many of the problems at first. After further scans I was told by the workshop that the root cause was a defective cable connection of the control unit to the BUS system and that it could cause these issues, so I would check it with a professional.

Okay, thanks a lot for the advice. Sounds like I'm on the right track then, as I also suspected a bus system defect. I'll check the wiring myself, but will probably have to take it to a workshop eventually. They quoted me 155€ for the repair, which is acceptable. Thanks!