Peugeot 3008 Overvoltage Fault Codes

Overvoltage, eh? That's tricky. I had a similar issue in my old Citroen C4 years ago, and it drove me nuts! Before you start pulling things apart, have you checked the alternator output? It could be putting out too much and frying everything. Also, how old is the battery?

Thanks. I haven't measured the alternator output yet, but I will. What voltage should I look for on the battery to know it's bad?

Definitely check the alternator first. Too much voltage can fry ECUs. A healthy battery should hold around 12.6 volts when the engine's off. If it's consistently dropping below 12.2V after sitting overnight, it's likely failing. Honestly, with those symptoms and the overvoltage code, I'd be tempted to take it to a workshop. Electrical issues can be a real pain, and you don't want to risk further damage.

Thanks for the advice. I took it to a local workshop. The battery was heavily discharged and defective, causing the overvoltage. The repair, including a new battery, cost 290€. Your suggestion to check the alternator output helped confirm the cause.