Q8 Passenger Seat Frozen: Electrical Adjustment Failure

I had a very similar issue with my 2020 Q7. As someone who has moderate experience working on cars but leaves electrical issues to professionals, I knew this needed proper diagnosis. The passenger seat stopped responding completely, no movement, no sound from the electric seat motors. Initially thought the seat switch was faulty, but the problem was actually a heavily discharged battery in combination with a wiring issue in the seat harness. The workshop diagnosed that the car seats power supply was affected by the weak battery, which apparently prioritizes the driver side controls when voltage is low. They had to: 1. Test the complete seat harness 2. Replace the battery 3. Recalibrate the seat control module Total cost was 290 Euro including parts and labor. The fix took about 2 hours. Could you share: Does the seat adjustment sometimes work intermittently? Have you noticed any other electrical issues? Does the seat position memory still function? When was the last battery check done? This information would help determine if your issue matches what I experienced with my Q7.

I own a 2022 Q8 with 156963 KM and had my last service done just 2 months ago. Thanks for sharing your experience. The passenger seat adjustment issue does not show any intermittent behavior, it is completely dead. The electric seat module shows the same error code consistently. The seat switch appears unresponsive regardless of time of day or engine running status. Just had my battery tested during the recent service and it showed good health, so I suspect this might be different from your case. The seat position memory buttons are also non-functional on the passenger side only. I will have it checked at the workshop since the electrical components in these seats are quite complex. Will update once I know the actual cause and repair costs. For others who might read this: has anyone specifically had the seat motor replaced on a Q8? Would be helpful to know the typical repair costs for this specific fix.

Thanks for the additional details about your Q8. Given that electrical system shows good health and the complete lack of any response from the power seats, this does point more toward a failed seat motor or severe wiring issue rather than the battery-related problem I had. The symptoms are quite different from my case, yours shows consistent failure while mine had occasional function. Since your automotive seat module consistently shows the error code, the workshop should be able to pinpoint the exact component faster. A few things to check before the workshop visit: Inspect visible seat wiring for any obvious damage, Test the fuse specifically for the passenger power seats, Check if the seat belt buckle is fully latched (some models have an interlock) The seat motor replacement on my Q7 (different issue, few months later) cost around 450 Euro for parts and labor. The tricky part was accessing all the seat wiring connections properly. Keep us posted on the final diagnosis, it will help others with similar power seats issues in the future.

Thanks everyone for the input so far. I took my Q8 to the workshop yesterday and got the diagnosis. Turns out the main seat motor assembly needs replacement, there was a complete failure of the motor unit, which explains the total lack of response in the seat adjustment system. The repair quote came in at 680 Euro including parts and labor. They need to remove the entire seat harness to access and replace the motor assembly. The workshop mentioned this is actually a known issue with some units from that production period. For those wondering, the repair involves: Complete seat disassembly, Replacement of the main motor unit, Testing of all seat adjustment functions, Recalibration of the seat memory system They said it will take about 4 hours to complete. Will get it fixed next week and report back on how it goes. Really hoping this solves the issue completely, as having non-functional power seats on the passenger side is quite inconvenient. Has anyone had this specific repair done recently? Would be good to compare costs and see if my quote is in line with others.