C30 passenger seat malfunction

Sounds frustrating! I had a similar problem once. Have you checked the battery? A discharged or defective battery can cause weird electrical issues with the power seats. Also, inspect the seat wiring harness under the seat for any obvious damage or loose connections.

Thanks, I'll check the battery voltage and wiring harness more thoroughly. If the battery is fine and the wiring appears intact, what's the next step?

If the battery checks out and the wiring looks good, it could be a faulty seat motor or even the seat control module itself. Honestly, diagnosing those issues can be tricky without the right tools. Taking it to a workshop might be your best bet. They have the diagnostic equipment to pinpoint the exact cause.

You were right. The workshop confirmed it was related to a voltage drop in the battery, causing the system to shut off the seat since it requires a steady voltage feed. The error code was pointing in that direction all along. Repair came to 290€. Thanks again for your help!