Audi S5 Nav System Failure Linked to Electrical Glitch

Having faced a similar situation with my 2016 Audi S4, I can share some relevant experience as someone who has dealt with several control module issues. The symptoms you describe match what I encountered, complete navigation failure coupled with electrical system warnings. The root cause turned out to be a software bug in the control module that required recalibration. My workshop diagnosed it as Programming of the control unit implausible and performed a complete software update. The fix involved reprogramming the ECU and updating several control modules. Total cost was 240 Euro and resolved both the navigation and electrical warnings. The repair took about 3 hours, but the car has worked flawlessly since then. To provide more specific guidance for your case, could you share: Current software version displayed in your MMI, Exact error codes from the electrical system, Whether issues started after a recent update or gradually appeared, If other electronic systems like radio or phone connectivity are affected This information would help determine if your S5 needs similar recalibration work or if there might be other factors involved.

Thanks for the detailed response. My last service was at 115000 KM just 3 months ago. The MMI shows software version 0139 and error code P1A3B. The navigation suddenly stopped during a drive, followed by the electrical warning. Radio and phone connectivity remain functional. Its worth noting that no updates were performed recently, so this seems to be a spontaneous control unit failure. I will try to book an appointment with an authorized workshop to check if a software reset might solve the issue, or if the control module needs more extensive work.

Based on your error code P1A3B and software version, this definitely sounds like the same control module issue I faced. In my case, the onboard diagnostics also indicated a spontaneous failure without any recent updates triggering it. Since your radio and phone systems still work, this reinforces my initial assessment that its a software bug rather than a hardware failure in the control unit. The workshop confirmed this pattern is fairly common in our model years when the ECU firmware reaches a certain operational time. The fact that it happened shortly after your service interval is likely coincidental, mine actually failed around 120000 KM. The control module simply reaches a point where it needs a software refresh, regardless of regular maintenance. My repair process included: Full system diagnostic scan, ECU reprogramming, Control module recalibration, Software version update to 0141 Getting it done at an authorized workshop is the right approach. They will have the specific firmware updates needed to resolve these control unit problems. Make sure they check for any related technical service bulletins, as there might be an updated fix procedure since my repair.

Thanks for sharing your expertise and repair details. The information about the software version and specific procedures is really helpful. My car has several matching symptoms, including the same electrical malfunction warning behavior you mentioned. I have scheduled an appointment at the workshop for next week. Based on the details about control module recalibration and ECU reprogramming you provided, I feel more confident about the potential fix. The vehicle software issues you experienced match mine exactly, from the navigation failure to the timing of the malfunction. I will make sure to ask them about checking technical bulletins and performing a complete onboard diagnostics scan. Since my error code P1A3B matches your case, hopefully a similar software reset and update procedure will resolve both the navigation and electrical warnings. Will follow up after the repair to confirm if the software update fixed the issue. The repair cost you mentioned gives me a good reference point for what to expect. Appreciate the thorough explanation of the troubleshooting steps and resolution process.