RS5 Trans Failure: Multiple Symptoms Point to Park System

Having dealt with similar transmission issues on my RS4 from 2018, I can share some relevant experience as someone with moderate expertise in performance car maintenance. The symptoms you describe match closely with what I encountered, rough shifting, startup problems, and transmission sensor warnings. After initial diagnosis, it turned out the transmission control unit was defective, affecting the gear shifter and gear linkage communication. The repair involved: Complete diagnostic scan, Removal and testing of the control unit, Replacement of the defective unit, Full system recalibration Total cost was around 1000 Euro including parts and labor. The workshop took about 2 days to complete everything, and the transmission issues were fully resolved. To provide more specific guidance, could you share: Build year of your RS5, Current mileage, Any recent maintenance or modifications, Specific error codes from the diagnostic scan, Whether the transmission failure occurred gradually or suddenly This information would help determine if your issue matches the transmission sensor problems I experienced or if there might be other underlying causes. Consider having a professional diagnostic scan done first before any major repairs, as this could save significant costs if the issue is more minor than initially suspected.

Thank you for the detailed response. My RS5 has 170424 KM and the last service was done 3 months ago during regular maintenance. The transmission failure happened suddenly while parking. The gear shifter simply stopped responding, and the park brake warning appeared together with the check engine light. The diagnostic scan shows error code P0706 which suggests transmission range sensor circuit problems. No modifications have been done to the car.

Thanks for providing those details. Based on your description, this indeed mirrors my experience even more closely than I initially thought. The P0706 error code on your RS5 points to the exact same transmission sensor issue I encountered with my RS4. The sudden failure during parking suggests the transmission range sensor is not properly communicating the neutral position to the control unit. In my case, this also triggered similar warning lights and prevented proper gear linkage operation. After my repair experience, here are the key points I learned: The P0706 code typically indicates the transmission sensor needs replacement, not the entire control unit, Labor costs were lower than initially quoted since accessing the sensor is less complex, The repair took about 4-5 hours rather than 2 days, Final cost was approximately 450 Euro including parts and labor Given your mileage and the sudden onset of symptoms, I strongly suspect you are dealing with a faulty transmission sensor rather than a more serious automatic transmission problem. This matches the common failure pattern at around 150000-180000 KM. Would recommend getting this addressed soon, as continuing to drive with faulty transmission sensors can lead to more extensive gear linkage damage.

Based on all this feedback, I really appreciate the detailed response and comparison to your RS4 experience. The matching P0706 error code and similar circumstances definitely help clarify what I'm dealing with. I feel much more confident now that this is likely a transmission sensor issue rather than a complete transmission repair, especially given the sudden failure while parking. I will schedule a repair appointment focusing specifically on the transmission sensor replacement, as that seems the most logical next step given our matching symptoms and error codes. The estimated 450 Euro repair cost is much more manageable than I initially feared. The shift lock and gear linkage issues happening around the 170000 KM mark align perfectly with the common failure pattern you mentioned. Since driving with faulty sensors could cause additional damage, I will keep the car parked until it can be serviced. Really helpful to know this is likely a contained issue with the neutral position sensors rather than a more extensive transmission problem. Thanks for sharing your repair experience, it has helped narrow down the probable cause and solution.