Astra parking assist failure

I had something similar with my Astra. Turned out to be a dodgy connection, like a loose wire on a lamp. Have you checked the wiring and plugs to the sensors themselves? That might be the culprit.

When you say 'dodgy connection', do you mean visibly broken wires or just loose plugs? Was it easy to find, or did you need to take it to a garage?

Mine wasn't visibly broken, just corroded inside the plug, so the connection was weak. It can be tricky to spot. If you're not confident with electrics, it might be worth getting a garage to take a look. They've got the tools to properly diagnose it. I ended up taking mine in.

Okay, I think I'll get it checked out. You were spot on! The shop found a defective cable / plug connection and it cost 95€ to fix. Cheers!