Audi SQ8 Transmission Nightmare: Gear Selector Fails

Having some experience with transmission issues, I faced a very similar problem with my 2019 Q8. The symptoms were nearly identical, unresponsive gear selector, inaccurate electronic display readings, and transmission problems. After multiple diagnostic tests, the workshop identified that the control unit managing the gear shift system was defective. The electronic display showing incorrect gear positions was directly linked to this faulty unit. The repair involved replacing the transmission control module and recalibrating the entire gear selector system. The total repair cost was 1000 Euro, which included parts, labor, and programming of the new control unit. Since the fix, the gear shift system has worked flawlessly, with accurate digital display readings and proper transmission operation. To provide more specific guidance for your case, could you share: Have you noticed any warning lights on the dashboard? Does the issue occur more frequently when the engine is cold or warm? Are there specific gear positions where the problem is most noticeable? Has the transmission fluid been checked recently? These details would help determine if your issue matches what I experienced with the automotive electronics system.

My SQ8 has covered 104280 KM since new and was last serviced 2 months ago. The gear shift problem started showing intermittently but has gotten worse. The car dashboard warning lights only appear when trying to engage gears. Thanks for the detailed response about the transmission control module, looking into that as a potential cause. The issue happens regardless of engine temperature, but the digital display shows especially erratic readings during cold starts. Currently waiting for a diagnostic appointment to check the automotive electronics and gear indicator system properly.

Sounds very similar to what I experienced with my Q8. The progression of the fault matches exactly, it started intermittently before becoming a constant issue. Since you mentioned the electronic display acts up particularly during cold starts, this further confirms my suspicion about the transmission control module. When the workshop diagnosed my car, they found that temperature variations were affecting the control unit's ability to properly communicate with the gear shift system. This caused both the erratic car dashboard readings and the physical shifting problems. One additional check worth requesting during your diagnostic appointment is the wiring harness connecting the gear selector to the control module. In some cases, damaged wiring can cause similar symptoms without requiring a full module replacement. The fact that your car was recently serviced but the problem persists suggests this is likely an electronic rather than mechanical transmission issue. Keep in mind that standard servicing might not catch control module faults unless specific diagnostic tests are run on the gear shift indicator system. Based on the similarities to my case, I suggest having them specifically test: The transmission control module functionality, Communication between the shift knob and control unit, Wiring integrity of the gear selector system, Accuracy of the gear indicator sensors

Based on your feedback and additional details about control module testing, I will have them check all those points during the diagnostic appointment. The progressive nature of the fault on my SQ8 matches the symptoms you described. I am more confident now that the issue lies within the transmission control module and sensor system rather than the mechanical components. The fact that the digital display shows incorrect gear positions especially during cold starts makes sense if temperature variations are affecting the control unit. While the 1000 Euro repair cost is significant, having a clear direction for the diagnosis is helpful. I will update once the automotive electronics testing is complete and they determine whether the control module needs replacement. For now, I am being extra careful with gear changes and monitoring the car dashboard warnings closely. If the workshop confirms this is the same gear indicator system fault you experienced, at least I know there is a proven fix available.