C30 immobilizer fault

Sounds familiar! I had a similar problem with my old Renault Megane. Key signal, car electronics, anti-theft system, remote start... all those were the suspects! Does it happen with both keys?

Good point. I've only tried one key so far. I'll try the other one, but if it's not the key itself, what else could it be? I'm not very familiar with car electronics.

Well, in my case, it wasn't the key itself. It ended up being an immobilizer fault, related to the key programming. Given the error code and symptoms you're describing, it might be worth visiting a workshop to get the key reprogrammed to the car. It's the anti-theft system doing its job, just a bit too enthusiastically!

Thanks, that's helpful! I tried the second key, and it's the same issue. I'll take it to the shop. They re-programmed the key and now it works. Cost me 45€. Thanks for pointing me in the right direction!