SQ5 Start-Stop Failure Linked to Battery Malfunction

Had similar issues with my 2020 Audi Q7 50 TDI. The start-stop system malfunction combined with unusual engine shutoffs pointed to a battery issue rather than just the idle stop feature acting up. The main symptoms matched exactly, unusual shutdowns, warning lights, and the automatic restart failing intermittently. After diagnostic testing, it turned out the original battery was heavily discharged and showing early signs of failure. The car would go into a limited eco mode to prevent complete system shutdown. The fix required: Full battery health analysis, Replacement of the main battery unit, Recalibration of the start-stop system, Reset of the battery management system, Clear stored error codes This was a serious issue that needed immediate attention since it affects core vehicle functions and safety systems. The unusual shutdowns while driving were particularly concerning as they could lead to dangerous situations. Worth noting that in newer Audi models, the start-stop system is deeply integrated with other vehicle electronics. When the battery starts failing, it can trigger multiple seemingly unrelated error codes. Getting it properly diagnosed at an authorized service center is crucial as they have the specific tools to analyze the battery management system.

Thanks for sharing your experience with the Q7. Your symptoms sound identical to what I faced with my SQ5. My starter motor was also showing signs of increased wear due to the failing battery constantly forcing emergency restarts. Curious, do you remember roughly how much the total repair cost? Also, have you experienced any similar issues since the fix? I want to make sure I budget correctly and know what to expect long term with the start-stop system.

After getting the repairs done, I can report zero issues with the start-stop system in my Q7. The battery replacement and system recalibration completely resolved the unusual shutdowns and warning lights. The starter motor wear was caught early enough to prevent any lasting damage. The total repair came to 290 Euro which covered the new battery, labor for installation, and full system diagnostics. This may seem steep for a battery issue, but modern hybrid-capable vehicles with start-stop systems require specialized batteries and proper integration with the vehicle electronics. Looking back, catching this battery issue early was crucial. A failing car battery in these sophisticated systems can cascade into more expensive problems if left unchecked. The start-stop system now engages smoothly every time, and the car performs exactly as intended. The repair has proven to be a worthwhile investment, no recurring issues in the months since the fix. The battery management system shows optimal performance, and those concerning emergency restarts are completely gone.

I took my SQ5 to the dealership last week after reading about similar experiences here. You were all spot on, it was indeed a battery issue affecting the start-stop system. The diagnostic showed my battery was operating at just 60% capacity despite the car being nearly new. The repair process was straightforward. They replaced the battery, recalibrated the system, and cleared all error codes. Total cost came to 275 Euro, which included labor and diagnostics. The starter motor thankfully showed no permanent damage from the constant emergency restarts. Been driving for a week now and the difference is night and day. No more unusual engine shutoffs, all warning lights are gone, and the idle stop feature works perfectly every time. The service advisor mentioned these issues are uncommon but can happen even in new vehicles if the battery gets deeply discharged. Thanks for helping me avoid a potentially bigger problem. The early intervention definitely saved me from more expensive repairs down the road.