VW Touareg ECU Failure Causing Major Power Loss

Had similar issues with my 2007 VW Passat 2.0T FSI. The engine control system showed comparable symptoms, power loss and multiple error codes during car diagnostics. The root cause was a defective main relay, which disrupted proper communication between the engine control module and various vehicle electronics. Initially suspected a full ECU failure, but thorough testing revealed the relay was intermittently failing. The repair process involved: Complete computer module diagnostic scan, Testing the power supply circuits, Replacing the main control relay, Resetting the control system, Verification testing This was a moderately serious issue since a failing main relay can cause complete vehicle shutdown. However, the fix itself was straightforward once properly diagnosed. The repair took about 3 hours at the shop. Most important is finding a shop with proper diagnostic equipment and experience with VW control systems. Request they perform a full diagnostic scan before starting repairs to avoid unnecessary parts replacement. Key warning signs to watch for: Unusual stalling, Electrical system fluctuations, Check engine light flashing, Multiple system errors appearing simultaneously

Thanks for sharing your Passat experience. That relay issue sounds very similar to what I am dealing with on my Touareg. The unusual stalling and system errors match exactly what I am seeing. I am curious about the repair costs for your ECU and vehicle electronics work. Would you mind sharing what you paid for the complete fix? Also wondering if you have had any recurring engine performance issues since the system reset and relay replacement? Hoping to get a ballpark figure before I visit a shop, since I want to make sure the quote I get is reasonable for this type of control system repair.

Since getting the relay replaced on my Passat, the engine performance and automotive electronics have been working flawlessly. The main relay replacement completely resolved those frustrating control system issues and unusual stalling problems. The total repair cost came to 120€, which covered the diagnostic work, parts, and labor. This was quite reasonable considering the complex nature of modern vehicle electronics and how critical the main relay is to proper system operation. After the computer module repair and system reset, I have not experienced any recurring issues. The engine runs smoothly, no more error codes appear, and the vehicle electronics function normally. Getting this fixed by a qualified technician who understood VW systems was definitely worth it, especially given how reasonable the cost turned out to be compared to a full ECU replacement. Make sure your mechanic does a complete diagnostic scan first, as this helped identify the exact problem in my case rather than unnecessarily replacing more expensive components.

Finally went to get my Touareg checked today after reading about your Passat experience. Really glad I did, as the issue turned out very similar. The mechanic found the main relay was indeed failing, causing those frustrating ECU problems and power losses. The total diagnostic and repair cost came to 145€, which seems fair based on what you paid. The shop ran a full control system check before starting any work, which helped identify the exact issue without replacing unnecessary parts. The vehicle electronics are now working perfectly after the system reset and relay replacement. Engine performance is back to normal with no error codes. What a relief to have this resolved without needing a complete ECU replacement or more extensive repairs. Thanks again for sharing your experience, it helped me approach the repair with more confidence and knowledge about what to expect.