VW Touran ECU Failure Causing Major Power Loss Issues

I had a nearly identical issue with my VW Tiguan 2017 gasoline model. With some experience working on VWs, I recognized similar symptoms, reduced power and engine control system warnings. The main relay was causing intermittent ECU communication problems. The computer module would out of nowhere lose connection, triggering check engine lights and limiting engine performance. After running multiple diagnostic tests, my workshop identified the defective relay as the root cause. The repair involved: Complete system reset, Replacement of the main relay, ECU testing to confirm proper communication, Clearing all stored error codes Total repair cost was 120€ including parts and labor. The car has been running perfectly since the fix, with no recurring engine control issues. Before suggesting specific solutions for your Touran, it would help to know: Are there any specific error codes stored? Does the issue occur more frequently when the engine is cold or warm? Have you noticed any other electrical system irregularities? What were the exact findings from your initial diagnostics? This information would help determine if your symptoms match the relay problem I experienced or point to different control system components.

Had my last service at 115000km and recently encountered nearly identical symptoms. After running car diagnostics, the workshop found the ECU was receiving incorrect signals due to a faulty crankshaft position sensor. The system reset alone did not resolve the engine control issues. The repair required: New crankshaft position sensor, ECU recalibration, Full diagnostic scan Total repair cost came to 280€. The engine performance returned to normal immediately after the fix. My suggestion would be to get a complete diagnostic scan to check if your control system is receiving proper sensor inputs. The symptoms you describe closely match what I experienced with the faulty sensor. The key is finding a workshop that specializes in VW engine control systems, as proper diagnosis requires specific diagnostic equipment for these models.

Thanks for sharing your repair experience. My VW Tiguan had identical issues, and your description of the crankshaft position sensor problems matches what I encountered before finding the relay issue. Vehicle electronics can be tricky since similar symptoms often have different root causes. After my relay replacement, I dealt with a bad crankshaft sensor too. The car diagnostics showed similar error codes as yours. The automotive electronics repair in my case included: Full sensor replacement, System reset and recalibration, Complete engine control testing, Error code clearing The repair cost was 290€, slightly more than yours but in line with typical sensor work. Since fixing both issues, the engine control system has been stable with no performance problems. Worth noting that proper diagnostic equipment is crucial, basic scanners often miss the connection between sensor data and engine control issues. Getting comprehensive car diagnostics saved time by pinpointing the exact problem.

Thanks for the detailed replies about the relay and sensor repairs. My ECU problems turned out to be related to a failing crankshaft position sensor indeed. After reading about your experiences with similar engine performance issues, I decided to have a complete diagnostic scan done. The workshop found: Multiple ECU communication errors, Inconsistent crankshaft position readings, Irregular engine control signals The repair involved: New crankshaft position sensor installation, Complete ECU recalibration, System-wide diagnostic testing Total cost was 280€ and the automotive electronics are working perfectly now. The engine performance returned to normal immediately after fixing the faulty sensor. For others facing similar vehicle electronics problems: Make sure to get a proper diagnosis from a shop with VW-specific diagnostic equipment. The symptoms can be similar for different underlying issues, so thorough testing is essential for proper ECU repair.