VW Beetle Won't Start, ECU or Fuel System Issue

Had a very similar issue with my 2013 VW Golf last winter. As someone with moderate experience working on VWs, I first suspected a major ECU issue when the engine light came on and the car would not start. After taking it to a workshop for engine diagnostics they found it was actually just corroded battery terminals causing poor connections. This was creating voltage drops that confused the ECU and triggered engine fault codes. The mechanic cleaned all battery connections, applied dielectric grease, and properly tightened everything. Total repair cost was 155€ including diagnostics. The symptoms you describe match my experience exactly, cranking but no start, persistent engine light, and sudden onset. Before assuming worst-case ECU failure scenarios, have your battery connections inspected thoroughly. To help diagnose this further: Has the battery been replaced recently? Are there any visible signs of corrosion on the terminals? Did you notice any electrical issues before the no-start condition? Have you scanned for specific fault codes? Let me know these details and I can suggest next troubleshooting steps based on my experience with VW electrical systems.

Had my last service at 90000km just 2 months ago and everything was fine then. No visible corrosion on the terminals and battery is relatively new, replaced 8 months ago. The ECU issue seems more complex as I already tested all electrical connections. Cleaned and checked all fuses too. The engine diagnostics scan showed P0201 and P0202 fault codes which point toward fuel injection problems. No electrical issues before this happened. Wonder if others had these specific codes with similar symptoms. Took it to a workshop today but they could not find the root cause yet. The engine light stays on even after clearing the codes. Starting to think this might be a more serious ECU failure requiring replacement rather than just a connection issue.

Good to hear back about those diagnostic results. Like your Beetle, my Golf showed similar fault codes before they found the real issue. While initial symptoms pointed to battery connections in my case, your P0201/P0202 codes definitely suggest fuel injector circuit problems, which matches my later experience with the same car. After my initial battery terminal fix, I actually faced a similar situation three months later with identical fault codes. Turned out the fuel injection control module was failing intermittently. The engine software was getting confused and shutting down the injector circuits as a safety measure. The workshop needed specialized engine diagnostics equipment to properly test the fuel injection system. They found the injector control circuits were unstable due to a failing control module, not the injectors themselves. The fix involved replacing the module and reprogramming the ECU, total repair came to 890€. Since you mention the codes persist after clearing, this strongly matches the pattern I experienced. The fact your battery and connections check out reinforces this could be a control module issue rather than just faulty injectors. Have you noticed any slight hesitation or rough running just before this complete failure? This was a telltale sign in my case that developed gradually before the no-start condition.

The engine light staying on after clearing codes definitely concerns me. A fellow forum member mentioned their Golf had similar symptoms from a failing fuel injection control module, which makes sense given my P0201/P0202 codes. Now that you mention it, I did notice slight engine surge and minor hesitation about a week before the complete failure. Just brushed it off since it was intermittent. The persistent engine fault codes even after clearing them seems to confirm this could be a control module problem rather than just bad injectors. Will have the shop specifically check the fuel injection control module tomorrow. They mentioned needing special engine software diagnostic tools they did not have today. Really hoping it is just the module and not a complete ECU failure, since that would be much more expensive to replace. Thanks for sharing your experience, it helps narrow down where to focus the diagnosis. Will update once I get more detailed test results from the specialized diagnostics.