VW Scirocco Start-Stop Failure Causing Engine Stalls

Had similar problems with a 2012 VW Golf TDI. The symptoms started with irregular idle stop behavior and unusual stalling during normal driving. The main issue turned out to be a combination of a failing starter motor and a heavily degraded battery. The automatic restart system was triggering incorrectly due to low voltage from the weak battery, causing the engine to stall unexpectedly. The repair required: Complete battery replacement, Starter motor rebuild, Reset of engine control modules, Recalibration of the start-stop system This was a serious repair that needed specialized diagnostic equipment. The battery issue was causing cascading problems, affecting multiple systems and triggering various error codes. Without proper voltage, the engine start sequence would fail intermittently. Important to note: The start-stop system has multiple safety checks. When these fail, the system can malfunction and cause stalling. Would strongly recommend getting the battery tested first, then having a full diagnostic scan to check the starter motor and related systems. A certified shop should be able to properly diagnose this using VAG-specific diagnostic tools to read all control modules, not just engine codes.

Thanks for sharing your experience with the Golf TDI. After reading about your similar issue, I am curious how much the total repair cost was. I recently had my 2009 Scirocco fixed with similar start-stop system problems and faulty battery symptoms. After the repair my engine start sequence works perfectly now and the battery issue seems resolved. However, I still notice occasional warning lights on cold starts. Did you experience any lingering issues after your repair was completed? It would be really helpful to compare costs, as these start-stop system repairs can vary quite a bit between shops and specific problems found.

Just got back from having my Golf TDI repaired, the total came to 290€ to fix the faulty battery that was causing our similar start-stop system problems. Great to hear your engine start sequence is working properly now after the repair. In my case, the battery replacement completely resolved the issues. The hybrid vehicle features like the idle stop function are now working flawlessly. I had no more warning lights or cold start problems afterward, so you might want to have those lingering warning lights checked out again. Sometimes these systems need a full reset after a new battery installation. The starter motor ended up being fine in my car, the heavily discharged battery was the root cause of all the symptoms. A properly functioning car battery is crucial for these automatic start-stop systems to work correctly. The diagnostic equipment showed the old battery was well below the required voltage levels.

Got my Scirocco back from the mechanic last week. The total repair came to 450€, which included a new battery, system diagnostics, and recalibration of the start-stop system. The mechanic found the starter motor was actually fine, just like in your case. The main culprit was indeed a failing battery causing the engine start problems. They also discovered some corroded connections that were affecting the idle stop function. After a thorough cleaning of the connections and the new battery installation, most issues cleared up. The cold start warning lights have mostly disappeared, though occasionally one still flickers. The mechanic mentioned this might need a software update to fully resolve. The price difference between our repairs makes sense, your shop did just the battery while mine included the extra electrical work. The start-stop system now engages smoothly, and the unusual stalling is completely gone. Definitely worth the investment to have it properly diagnosed and fixed.