Audi RS7 ECU Failure Symptoms and Repair Guide

Based on my experience with a 2016 RS6, I encountered a very similar issue with the vehicle electronics and reduced power mode. Having worked on several performance cars, I would say I have some decent experience with these systems. The root cause in my case was a defective main relay causing intermittent power supply issues to the engine control unit. This resulted in multiple error codes and the system defaulting to reduced power mode to protect the engine performance. The repair process involved: Complete system diagnostic scan, Testing of the power supply to the computer module, Replacement of the main relay, Full system reset and code clearing Total repair time was about 2 hours and cost 120 Euro including parts and labor. After the fix, all systems returned to normal operation with no recurring issues. However, to provide more specific guidance for your case, could you share: What error codes are you seeing? Does the reduced power mode occur immediately upon startup? Have you noticed any warning lights before this started? Any recent work done on the automotive electronics? These details would help determine if your issue matches what I experienced or if there might be other factors to consider.

Thanks for sharing your experience. After running multiple car diagnostics yesterday at the dealership, they found that the issue differs from what you encountered. My system reset attempts were unsuccessful and the control system is showing consistent failure patterns rather than intermittent problems. Latest service was done at 105000 KM with no issues reported then. The workshop quoted 1500 Euro for a complete engine control unit replacement, saying the automotive electronics require a full reprogramming. They mentioned this is critical for maintaining proper engine performance. Looking for a second opinion on whether this quote and diagnosis makes sense.

Thanks for the additional details on your RS7 case. Having gone through a similar diagnostic process with my RS6, I can confirm that consistent failure patterns in the engine control unit often point to a more serious issue than intermittent relay problems like I initially experienced. The 1500 Euro quote for a complete control system replacement and reprogramming actually aligns with typical repair costs for these high-performance vehicles. The automotive electronics in these models are highly sophisticated, and proper engine performance depends heavily on precise programming of the new unit. In my case, I was fortunate that the issue was just the relay, but when dealing with consistent control unit failures, partial repairs rarely solve the problem. The workshop is correct about needing both the physical unit replacement and complete reprogramming, this ensures all vehicle electronics communicate properly. Some key points to consider: Control unit replacement requires specialized programming equipment, The new unit must be properly coded to your specific vehicle configuration, All engine performance parameters need precise calibration, The entire process typically takes 4-5 hours of shop time Based on my experience with similar engine control issues, I would proceed with the repair at that price point, especially given the consistent nature of the failure.

I appreciate the thorough explanation regarding my RS7. After comparing both diagnostic results and repair approaches, I agree the computer module needs full replacement. The consistent ECU failures align with what the shop found, unlike the intermittent issues you experienced with your relay. The 1500 Euro price seems reasonable for engine control unit replacement and complete reprogramming, considering the complexity of vehicle electronics and specialized equipment needed. The fact that my system reset attempts failed consistently supports their diagnosis. My only remaining concern is whether I should get the repair done now or if I can safely drive it for another few weeks in reduced power mode. Based on the clear control system issues, I will likely proceed with the recommended ECU repair soon to restore proper engine performance and avoid potential additional problems. Will update once the work is completed to share the final outcome. Hopefully the fix will be as successful as your relay replacement was, just at a higher price point due to the more extensive repair needed.