Mercedes Viano door electronics fault repair

I had something similar on my Vito, though I didn't check the error codes. Keyless entry stopped working on the driver's door. A 'wiring fault' is probably spot on. These vans are known to have issues with the wiring loom where it passes from the body into the car door. Constant opening and closing fatigues the wires over time.

Can you elaborate on which part of the wiring loom is most susceptible to failure? Was it a specific wire or connector within the door electronics or door handle itself? Any details would be helpful before I start inspecting the car door's wiring.

Honestly, I didn't dive too deep myself. I just wiggled the wires near the door hinge and it temporarily fixed the problem, which confirmed the wiring fault. I'd recommend taking it to a workshop. They can properly diagnose the exact point of failure and repair it properly. Messing with car door wiring can be tricky if you're not sure what you're doing.

Understood. I appreciate the advice. I took the Viano to a workshop, and they confirmed a defective cable or plug connection within the door mechanism, as suspected. The repair cost was 95€. The keyless entry is now functioning correctly again.