SQ7 Passenger Seat Frozen, Power Control Failure Alert

Having some experience working on cars, I encountered a similar issue with my 2018 S8 last winter. The automotive seat functions completely died, with both electric seat adjustments failing to respond. Based on your description, this sounds exactly like what I dealt with. In my case, the root cause was a heavily discharged battery affecting the seat motor systems. The car seats appeared completely dead, similar to your situation. After checking the seat wiring and fuses like you did, I took it to a workshop. The repair involved: Full battery diagnostic test, Replacement of the failing battery, Reset of the seat control modules, Testing all electric seat functions Total repair cost was 290 Euro including parts and labor. The work took about 2 hours to complete. Before suggesting more specific solutions, could you share: Have you noticed any other electrical issues recently? Does your battery warning light show on the dashboard? How old is the current battery? Are there any other error codes besides the seat-related one? This would help determine if you are facing the same underlying battery issue I had.

Having some experience working on cars, I encountered a similar issue with my 2018 S8 last winter. The automotive seat functions completely died, with both electric seat adjustments failing to respond. Based on your description, this sounds exactly like what I dealt with. In my case, the root cause was a heavily discharged battery affecting the seat motor systems. The car seats appeared completely dead, similar to your situation. After checking the seat wiring and fuses like you did, I took it to a workshop. The repair involved: Full battery diagnostic test, Replacement of the failing battery, Reset of the seat control modules, Testing all electric seat functions Total repair cost was 290 Euro including parts and labor. The work took about 2 hours to complete. Before suggesting more specific solutions, could you share: Have you noticed any other electrical issues recently? Does your battery warning light show on the dashboard? How old is the current battery? Are there any other error codes besides the seat-related one? This would help determine if you are facing the same underlying battery issue I had.

Thanks for the detailed info about the battery theory. Just checked my fault codes again and pulled out P0659 and P0657, both related to the actuator supply voltage. The seats have been acting up since my last service at 193193 KM about 2 months ago. No other electrical problems noticed and battery seems fine, car starts perfectly every time. The automotive seat functions just stopped working suddenly while driving. The seat wiring suggestion makes sense given those codes. Will probably need to have a technician trace the electric seat circuits to pinpoint where exactly the power is getting interrupted. Just hoping its not a full seat motor replacement since those can get expensive on these models.

Thanks for the detailed info about the battery theory. Just checked my fault codes again and pulled out P0659 and P0657, both related to the actuator supply voltage. The seats have been acting up since my last service at 193193 KM about 2 months ago. No other electrical problems noticed and battery seems fine, car starts perfectly every time. The automotive seat functions just stopped working suddenly while driving. The seat wiring suggestion makes sense given those codes. Will probably need to have a technician trace the electric seat circuits to pinpoint where exactly the power is getting interrupted. Just hoping its not a full seat motor replacement since those can get expensive on these models.

Having gone through this exact situation with my S8, those fault codes actually point to a different issue than what I initially suspected. The P0659/P0657 codes typically indicate a problem with the seat control module or power seat wiring harness, rather than the battery issue I experienced. Since you mention the problems started after your service, I would inspect the seat harness connections first. On my car, there was a damaged wire in the passenger seat harness that was causing intermittent power seat failures. The constant seat movement eventually wore through the protective covering. The seat motor itself is likely fine if the issue appeared suddenly. A failing seat motor usually shows gradual symptoms first, like slow or jerky movements. The power seats typically stop working completely when there is a wiring or control module problem. Some things to check: Seat harness connectors under the seat for loose connections, Wiring routing points for any pinched cables, Seat control module connections In my case, the harness repair cost was 180 Euro plus labor. Much better than the 800 Euro+ for a new seat motor assembly. Repair time was around 3 hours since they had to partially disassemble the seat to access all the connections.

Having gone through this exact situation with my S8, those fault codes actually point to a different issue than what I initially suspected. The P0659/P0657 codes typically indicate a problem with the seat control module or power seat wiring harness, rather than the battery issue I experienced. Since you mention the problems started after your service, I would inspect the seat harness connections first. On my car, there was a damaged wire in the passenger seat harness that was causing intermittent power seat failures. The constant seat movement eventually wore through the protective covering. The seat motor itself is likely fine if the issue appeared suddenly. A failing seat motor usually shows gradual symptoms first, like slow or jerky movements. The power seats typically stop working completely when there is a wiring or control module problem. Some things to check: Seat harness connectors under the seat for loose connections, Wiring routing points for any pinched cables, Seat control module connections In my case, the harness repair cost was 180 Euro plus labor. Much better than the 800 Euro+ for a new seat motor assembly. Repair time was around 3 hours since they had to partially disassemble the seat to access all the connections.

Thanks for that detailed explanation about the wiring. After checking those codes again (P0659 and P0657), I think you might be right about the seat wiring harness being the culprit rather than the seat motor. Makes total sense that the issue popping up right after the service could mean something got disconnected or damaged during the work. I took a closer look under both seats and noticed the electric seat wiring looks a bit stressed where it connects to the seat adjustment switches. Going to have my regular shop check the connections and trace the circuits since they know the car well. If we catch a wiring issue early it should save me from a much more expensive seat motor replacement down the line. Really hoping its just a loose connection or pinched wire causing the electric seat system to fail. Will update once I get it diagnosed properly. Good to know the harness repair was relatively affordable in your case, definitely beats paying for new seat motors or control modules. Thanks again for helping narrow down the likely cause with those fault codes. The automotive seat electrical systems are pretty complex on these newer models so having some direction on where to look is super helpful.

Thanks for that detailed explanation about the wiring. After checking those codes again (P0659 and P0657), I think you might be right about the seat wiring harness being the culprit rather than the seat motor. Makes total sense that the issue popping up right after the service could mean something got disconnected or damaged during the work. I took a closer look under both seats and noticed the electric seat wiring looks a bit stressed where it connects to the seat adjustment switches. Going to have my regular shop check the connections and trace the circuits since they know the car well. If we catch a wiring issue early it should save me from a much more expensive seat motor replacement down the line. Really hoping its just a loose connection or pinched wire causing the electric seat system to fail. Will update once I get it diagnosed properly. Good to know the harness repair was relatively affordable in your case, definitely beats paying for new seat motors or control modules. Thanks again for helping narrow down the likely cause with those fault codes. The automotive seat electrical systems are pretty complex on these newer models so having some direction on where to look is super helpful.