Alphard Passenger Seat Failure

It sounds like there could be an issue with the seat harness or the seat motor itself. Has the battery been checked recently? A heavily discharged or defective battery can sometimes cause electrical gremlins in these systems.

That's interesting! I haven't checked the battery specifically. Would a low battery really stop just one seat from working? Everything else seems fine, lights, starting, etc.

Yes, it's possible. Modern cars are very sensitive to voltage drops. The seat motor may require a certain voltage to operate correctly, and if the battery is weak, it might not be providing enough power. Although other components appear to be working it is still possible for the battery to be the source of the issue. I would suggest getting the battery tested, and then consider visiting a workshop.

Thanks for the advice! You were right, it turned out to be the battery causing the problem. I got it replaced, and the seat is working perfectly again. Cost me 290€ at the garage, all in. Appreciate the help!