Caravan Immobilizer Fault

Sounds like immobilizer trouble, especially with key recognition. Does the security light come on when it happens? That could mean the transponder signal isn't being read. Remote start systems can also cause this. What's the exact fault code?

Yeah, the security light is on. It's steady when the ignition is on, but flashes when it won't start or dies. No remote start installed. The fault code says 'key transponder signal error'. How can I be sure before I try bypassing the immobilizer?

Flashing security light and that fault code really point to a key programming issue or the immobilizer ECU itself. Could need reprogramming or replacement. I'd take it to a workshop with the right tools to diagnose it.

Thanks, that confirms what I thought. Took it to a shop, and the key wasn't programmed right. They re-flashed the transponder for 45€ and it starts fine now.