Barchetta keyless entry fault

I had a similar problem with my old 2012 BMW 3 series. The central locking would randomly fail, and it turned out to be a frayed wire in the door harness where it goes into the door itself. Have you checked the wiring loom between the door and the body? That's a common place for wires to break.

Interesting! So, was it obvious when you looked, or did you have to really dig around to find the broken wire? Any specific area in the loom that's more prone to damage?

It wasn't immediately obvious, to be honest. I had to peel back the rubber boot and inspect each wire individually. It was a tiny break, but enough to cause the issue. But in your case, since you already suspect the door handle electrics, the problem could also be directly at the door actuator or the plug connection. It might be best to take it to a workshop, so they can properly diagnose where the fault lies. The error code should give them a pretty good starting point.

Took your advice and booked it in. Turns out it was exactly as we thought – corroded connector in the door. New connector and a bit of wiring repair, all in for 95€. Keyless is back, and no more error codes!