VW Polo Start-Stop Failure Causing Random Engine Cuts

Recently dealt with similar symptoms on a 2016 VW Golf TDI. The automatic restart system completely failed, followed by unusual engine stalling. The battery diagnostic showed severe degradation affecting the start-stop functionality. The issue typically stems from either: 1. Battery heavily discharged or defective 2. Starter motor wearing out from frequent start-stop cycles 3. Failed voltage management system In my case, the original AGM battery had degraded below the minimum threshold required for start-stop operation. The starter motor showed additional strain from compensating for the weak battery. The repair required: Full battery system diagnostic, Replacement of AGM battery, Voltage management system reset, Start-stop system recalibration This was a serious repair requiring specialized diagnostic equipment and proper coding. A standard battery replacement would not resolve the issue, as start-stop systems need specific AGM batteries with higher cycling capacity. Recommend having this checked at a workshop with VW diagnostic capabilities, as generic scan tools often miss start-stop specific fault codes. The engine stalling indicates this should be addressed promptly to prevent potential starter motor damage.

Thanks for detailing your experience with the VW Golf. Your symptoms match exactly what happened with my Polo, really helpful info about the AGM battery being the core issue. Quick question, do you remember roughly how much you paid for the full fix? Also, has the start-stop system worked flawlessly since the repair, or have you noticed any quirks with the automatic restart? Just want to get an idea of costs before heading to the dealer. The eco mode has been acting up too lately, wondering if that might be related to these hybrid vehicle electrical gremlins.

Had the repair done last week actually. Total cost came to 290€ for replacing the AGM battery and getting everything recalibrated. Since then, the automatic restart feature works perfectly again, no more issues with unusual engine shutoffs or warning lights. The eco mode troubles you mentioned were likely connected to the battery problems. A weak battery can trigger various electrical system warnings. The start-stop system really needs a strong, properly functioning battery to operate correctly. What really made the difference was getting the voltage management system properly reset after the battery replacement. The starter motor now engages smoothly every time without any hesitation. Would definitely suggest having your Polo checked soon, as these symptoms typically worsen if left unaddressed.

I took my Polo to the dealership yesterday after reading about your experience. Really glad I did, turns out you were spot on about the battery being the main culprit. My repair came in at 310€, slightly more than yours but included a full system check. The automatic restart now works perfectly again. The starter motor engages smoothly and the unusual shutoffs have completely stopped. They also fixed the eco mode issues, which as you mentioned, were directly related to the battery problems. The technician confirmed the original battery had degraded below the minimum threshold for the start-stop system to function properly. They installed a new AGM battery, reset the voltage management system, and recalibrated everything. The hybrid vehicle systems are all working as they should now. Thanks for the detailed advice, saved me from trying cheaper fixes that wouldn't have solved the underlying issue. For anyone else reading this with similar symptoms, definitely worth getting it checked by a qualified workshop with proper diagnostic equipment.