VW Arteon ECU Failure: Repair Solutions Revealed

Had a similar issue with my VW Passat (2018) with reduced engine performance and persistent error codes. With moderate experience in car repairs, I initially thought it was just a software glitch that needed a control system reset. After multiple error codes kept appearing, I took it to a workshop specializing in automotive electronics. Turns out the main relay was defective, causing unstable power supply to the ECU. The engine control malfunction symptoms were identical to what you describe, reduced performance and multiple stored error codes. The fix was straightforward once properly diagnosed, replacing the main relay restored proper ECU function. Total repair cost was 120€ including diagnostic work. The vehicle electronics have worked flawlessly since then. To better assist with your specific case: What model year is your Arteon? Which error codes are being stored? Does the reduced performance occur out of nowhere or under specific conditions? Have you noticed any other electrical issues? This information would help determine if your issue matches the relay problem I experienced or points to a different ECU repair need.

Just had the computer module diagnosed at my last service (139533km). The car diagnostics showed multiple error codes (P0234, P0299) related to boost pressure. Workshop reset the control system but errors returned within days. The reduced performance happens mainly during acceleration after the engine is warm. No other electrical problems noted. Based on your relay experience, I will have them check the power supply components before replacing the entire engine control unit. Appreciate the detailed insight on your repair solution. Will report back after the next diagnostic session to help others with similar vehicle electronics issues.

Thanks for the additional details about the error codes. Since my Passat repair, I have learned that boost-related codes like P0234 and P0299 often point to different root causes than my relay issue. Given that the system reset only temporarily resolved the problem, and the errors specifically relate to boost pressure, you should have the turbo system components checked before suspecting ECU problems. The workshop should inspect: Wastegate actuator functionality, Boost pressure sensors, Vacuum lines for leaks, Turbocharger mechanical condition In my case, the relay issue caused unusual ECU problems across multiple systems. Your focused boost pressure errors suggest a more specific underlying cause. The engine control unit is likely responding correctly to faulty sensor inputs or mechanical issues rather than being defective itself. Checking power supply components is still worth doing, but I would prioritize inspecting the turbo system first. A proper diagnostic of these components typically costs between 80-150€ and could save you from an unnecessary ECU repair or replacement. Keep us updated on what the inspection reveals. Your feedback will help build knowledge about these control system issues for other owners.

Thank you for the feedback regarding the turbo system inspection suggestions. Have scheduled another diagnostic session focusing specifically on the boost-related components. The workshop confirmed they will check all the items mentioned, wastegate, sensors, vacuum lines and turbo condition before exploring any ECU repair options. The systematic approach makes sense since the engine control unit may just be reacting to mechanical issues rather than being faulty itself. Will definitely ensure they verify the electrical supply components as well, even though the error codes point more toward boost pressure problems. Cost estimate for the complete diagnostic procedure is 120€ which seems reasonable given the scope. Will update the forum once they complete the inspection and identify the root cause. Hopefully this helps narrow down typical control system issues for other Arteon owners experiencing similar symptoms.