SQ7 Sudden Shutdowns, Start-Stop System Failure Alert

Had similar problems with my 2020 Audi S5. The automatic restart system was failing intermittently and the start-stop system showed error codes. After thorough diagnostics, the issue traced back to a failing voltage management module and a heavily discharged battery. The main symptoms matched yours, unusual shutoffs during driving and start-stop system malfunctions. The starter motor would occasionally struggle, especially during eco mode activation. The fix required: Replacement of the voltage management module, Installation of a new AGM battery, System recalibration of the start-stop function, Reset of the engine control unit This was a serious electrical system issue that could have led to complete vehicle failure if left unaddressed. The battery discharge was damaging other electrical components over time. For your SQ7, recommend getting the voltage management system checked first, as these symptoms often point to more than just a battery issue. The starter motor and related circuits should also be tested, given the automatic restart problems. Worth noting that modern start-stop systems are complex and interlinked with multiple vehicle systems. Professional diagnostic equipment is essential for proper troubleshooting.

Thanks for the detailed response about your S5 electrical problems. The symptoms you described sound exactly like what I am experiencing with my SQ7, especially the unusual engine stalling and battery issues. I plan to have a full voltage management check done based on your advice. Could you share how much the complete repair ended up costing? Also, has your car had any recurring issues with the automatic restart or eco mode since the fix?

Since the repairs, my S5 has been running perfectly with zero battery issues or problems with the automatic restart system. The start-stop system now engages smoothly every time, and I have not experienced any more unusual shutoffs while driving. The total repair cost came to 290 Euro for diagnosing and replacing the faulty battery, which was heavily discharged and causing the system malfunctions. The voltage management module actually turned out to be fine after testing, so that saved some money. Eco mode works flawlessly now and the engine start reliability is back to normal. The mechanic explained that a degraded battery can cause cascading issues with modern start-stop systems, which is exactly what was happening in my case. The investment was worth it for the peace of mind, knowing the electrical system is working as designed. Make sure your mechanic does a complete battery health check, as this seems to be a common trigger for these symptoms.

Here is my update after visiting the mechanic for my SQ7 issues. The diagnosis matched what was mentioned, my hybrid vehicle had a significant battery issue causing the unusual engine stalling. The mechanic found the original battery was failing prematurely and affecting multiple systems. The voltage was too low to support proper automatic restart function. After replacing the battery and recalibrating the system, the idle stop feature works perfectly again with no more unexpected shutdowns. Total cost was 340 Euro including: New AGM battery, System diagnostics, Recalibration of start-stop, Labor Been driving for a week now without any problems. The automatic restart engages smoothly and the warning lights are gone. Really glad I got this fixed before it caused more issues. Thanks again for pointing me in the right direction, saved me from multiple mechanic visits trying to diagnose the problem.