Peugeot Partner Fuel Flap Problem

The symptoms you describe, particularly the error messages and the fuel flap issue, do point to a potential problem with the fuel flap release mechanism, possibly the electric actuator. Are you able to hear any sound, like a motor whirring, when you try to release it via the key fob?

No sounds at all, completely dead. Is that a common thing? Where exactly is this actuator located? Maybe I can check the linkage.

Given that there's no sound, it does seem the electric actuator has failed. A defective linkage is also a possibility. I'd recommend having a workshop diagnose the issue. It is likely that it needs replacing.

Cheers! Took your advice and got it checked. Turns out the actuator was shot. Cost me 210€ to get it fixed, but at least I can fill up the tank again!