VW Virtus ECU Failure Causes Sudden Power Loss

Had similar issues with my 2017 VW Polo TSI last year. The symptoms matched exactly, sudden power loss and engine warning light while driving. After running car diagnostics, our shop discovered it was actually a faulty main relay rather than a complete ECU failure. The main relay acts as a critical component in the engine control system, managing power distribution to the ECU. When it fails, it can mimic symptoms of a complete computer module failure. The repair involved replacing just the main relay assembly and recalibrating the engine management system. This was a significantly less complex fix than replacing the entire control unit. While still a serious issue that required immediate attention to prevent potential engine performance problems, it was far less invasive than a full ECU replacement. Worth getting a specialized automotive electronics shop to perform targeted testing of the relay circuit and ECU components separately. Often, individual components can be repaired or replaced without needing a complete unit swap. This approach saved considerable time and resources in my case. The repair resolved all symptoms completely and the car has been running perfectly since then with no recurring issues.

Thanks for sharing that experience. I also faced the exact same situation with my VW Virtus last summer. Good to hear your ECU repair was less complicated than initially diagnosed. The main relay fix makes total sense and definitely sounds like a smarter first step than replacing the whole engine control module. Just curious, do you remember roughly how much you ended up paying for the relay replacement and system reset? And has everything stayed stable with your engine performance since the fix? My mechanic quoted 1200€ for a full ECU replacement which seems excessive if the relay could be the actual culprit.

Really glad you followed up. After seeing the mechanic last week, my suspicions about the main relay being the root cause were confirmed. The total repair cost came to 120€, which included replacing the defective relay and recalibrating the engine control unit. The automotive electronics specialist identified that the ECU itself was functioning properly once the faulty relay was replaced. No need for that expensive complete computer module replacement that was initially suggested. My engine performance has been completely stable since the repair, no warning lights, no power loss issues, and the control system is working exactly as it should. Going on 6 months now with zero problems. Looking at your quoted price of 1200€ for a full ECU replacement, I would strongly suggest getting a second opinion from a shop that specializes in automotive electronics diagnostics. They can properly test if your engine control unit truly needs replacement or if its just a relay issue like mine was.

After getting multiple opinions, I finally took my VW Virtus to a specialized automotive electronics shop last week. The technician found the same relay problem mentioned here and fixed it for just 180€, including parts and labor for the system reset. The ECU repair process was straightforward, they replaced the faulty main relay and recalibrated the control system. The whole job took about 2 hours. Really glad I questioned that initial 1200€ quote for a complete ECU replacement. Been driving for a few days now and the engine performance is back to normal. No more power loss issues or warning lights. The control system is working perfectly. Just shows how important it is to get a second opinion from specialists who really understand automotive electronics before agreeing to major repairs. Thanks again for sharing your experience, it definitely helped me avoid an unnecessary expensive repair.