Peugeot 607 start stop failure

I had exactly the same thing happen on my 607! That start-stop system can be a right pain. I'm guessing it could be your battery. Is it holding a charge properly? These cars are super sensitive to voltage drops, and a dodgy battery will throw everything out of whack.

Interesting! I didn't think about the battery. It's the original one, so probably getting on a bit. Did yours throw up any other weird symptoms or was it just the start-stop playing up?

Just the start-stop being a nuisance and randomly cutting out at traffic lights, which is not great, haha! I'd get the battery checked professionally if I were you. Probably best to get it changed anyway, it's likely causing your problems. I ended up taking mine to a workshop and they sorted it.

Cheers for the advice! I'll definitely get the battery checked out ASAP. Sounds like that's the most likely culprit. I’ve already scheduled a visit to the workshop. They confirmed that the battery was indeed defective. The repair will cost me around 290€. Thanks again!