SQ8 Multiple Electrical Failures, Nav System Down

As someone with moderate experience working on Audi vehicles, I encountered a very similar situation with my 2020 S7. The symptoms were nearly identical, complete navigation failure followed by multiple electrical fault messages. The issue turned out to be related to a faulty control module that required both a software update and recalibration. My workshop diagnosed it as Programming of the control unit implausible, which basically means the module lost its correct programming parameters. The fix involved a complete software update of the control unit, plus recalibration of several connected systems. Total cost was 240 Euro, and it resolved all the electrical issues completely. The workshop mentioned this was a known software bug that affected several models in that generation. Before suggesting specific solutions though, could you share: Has the check engine light come on? Are you experiencing any other electrical issues besides navigation? Have you recently had any battery issues or electrical work done? Can you access the vehicle settings menu at all? This information would help determine if your issue matches what I experienced and whether a similar fix might work for your SQ8.

Last service was done at 80000 KM. After reading your reply and experiencing similar symptoms myself, I ran an onboard diagnostics scan which showed multiple fault codes related to the control unit. The check engine light hasnt appeared yet, but I noticed the battery voltage seems slightly lower than usual. The vehicle settings menu is completely inaccessible now. Interestingly, I can confirm no recent electrical work was done, and these issues started suddenly during normal operation. The software reset procedure mentioned in the manual didnt help at all. My guess is that this could indeed be related to the control module programming issue you described, especially given the similar symptoms in other Audi models. Im planning to schedule a workshop visit to have them perform a complete software update on the control unit. Thanks for sharing the cost reference, helps with setting expectations.

Glad to help further with the issue. After seeing your diagnostic results, I'm even more convinced this matches the control unit programming issue I encountered. The inaccessible settings menu and battery voltage irregularities are particularly telling, these were exact precursors to my S7's ECU problems. The onboard diagnostics showing multiple fault codes related to the control unit strongly suggests we're dealing with the same software malfunction I experienced. In my case, the workshop confirmed that erratic battery voltage can sometimes trigger software corruption in these control modules. When my S7 had similar symptoms, the software reset from the manual also failed to resolve anything. The complete control unit reprogramming was necessary because the original software had become corrupted. The technicians explained that these systems are particularly sensitive to voltage fluctuations. Based on your description and my experience, I strongly recommend having them: 1. Run a full diagnostic scan 2. Check for any control unit updates 3. Verify battery health 4. Perform complete ECU reprogramming if needed The fix should be similar in cost to what I paid, possibly slightly higher if the battery needs attention too.

Based on your thorough explanation and the battery voltage information, I will definitely proceed with scheduling a workshop visit. The multiple fault codes from my diagnostic scan combined with the complete settings menu lockout really point toward the control unit programming issue you experienced. The failed software reset attempt and similarity of symptoms to your S7 case make me confident that a full ECU reprogramming will likely resolve these issues. Your suggestion about checking the battery health also makes sense given the voltage readings Im seeing. I have scheduled an appointment for next week and will ask them to perform the complete diagnostic protocol you outlined, including the software update and control unit recalibration. Its reassuring to know the fix should be relatively straightforward, even if multiple systems need reprogramming. The cost estimate helps with planning, and Ill make sure to mention the potential connection between battery voltage and software corruption when I bring it in. Ill also ask them to check for any pending software updates that might prevent this from happening again.