Audi Starting Issue: Hidden ECU Failure Warning Signs

I had a very similar issue with my 2014 Audi A1 1.2 TFSI last winter. Having some experience with basic car maintenance, I first suspected the battery too, but the problem turned out to be quite different. After the engine failed to start and showed similar symptoms, dashboard lights but no cranking, I took it to a workshop. The check engine light was also flashing intermittently, which pointed to a potential ECU issue at first. The technicians ran a full diagnostic scan and found that the battery cable connections were severely corroded and loose, causing poor electrical contact. This created symptoms that mimicked more serious electronic problems like ECU failure or engine software issues. The fix involved cleaning the terminals, replacing the connectors, and ensuring proper tight contact. Total cost was 155 Euro for parts and labor. Before suggesting more specific solutions, could you share: Have you checked the battery terminals for corrosion or loose connections? Does this happen consistently or intermittently? When was your last battery replacement? Have you noticed any other electrical issues recently (dim lights, slow power windows)? This information would help determine if your case might be similar to what I experienced or if it points to a different issue entirely.

Thanks for the advice regarding potential electrical issues. Just had the car serviced at 167687 KM last month and everything checked out fine then. The problem started occurring consistently over the past week. Initially thought it was an engine fault, but after reading your experience, I checked the battery terminals, they seem clean and properly connected. The engine surge symptoms and intermittent engine fault codes make me think its more likely an ECU issue or fuel injection problem since all other electrical systems (lights, windows, etc) work perfectly. Will get it properly diagnosed to be sure though. Worth noting that during the last service they updated some software, so wondering if that could be related to the current ECU failure symptoms.

This definitely sounds like it could be software-related, especially given the timing with your recent service. My A1 actually experienced very similar symptoms after a software update, complete failure to start despite all electrical systems working fine. The engine diagnostics on my car revealed that the ECU was misinterpreting signals from the fuel injection system following the update. The fuel injection system itself was functioning correctly, but the ECU was preventing engine start as a safety measure due to incorrect readings. In my case, the fix required the workshop to: 1. Perform a complete ECU reset 2. Reinstall the engine control software 3. Recalibrate the fuel injection parameters The total repair cost came to 320 Euro, mostly labor since no parts needed replacement. The engine has been starting perfectly since then, with no engine surge issues or fault codes. Based on your description and the timing with the recent software update, I strongly suspect youre dealing with a similar ECU issue rather than a mechanical problem. Would recommend getting the ECU software specifically checked before exploring other potential causes. One thing to try before taking it to the shop: disconnect the battery for about 30 minutes to force an ECU reset. This sometimes resolves software-related starting issues, though in my case it needed professional intervention.

Thanks for sharing those repair details. Following up on my case: took it to a different workshop yesterday and your suspicions about the ECU were spot on. The diagnostic scan showed the ECU was indeed misinterpreting sensor data after that recent software update. The mechanic explained the engine stalling and starting issues were caused by corrupted software parameters in the ECU. They performed a complete system reset and reinstalled the engine control software, which resolved both the check engine light and starting problems. Total repair cost was 290 Euro, slightly less than your case since they had a newer diagnostic system that reduced the labor time. The engine now starts perfectly and all fault codes are cleared. Really appreciate the suggestion about the software angle, saved me from unnecessarily exploring mechanical issues. Will definitely keep an eye on any future updates to avoid similar ECU problems.