VW Touran ECU Lock Blocks Fault Code Clearing

Had a similar issue with my 2019 VW Tiguan. As someone with some DIY auto repair experience, I initially tried clearing the fault codes with a basic OBD scanner, but faced the same lock issue. The root cause was undervoltage in the vehicle electrical system, which triggered multiple control unit errors and activated the fault memory protection. The workshop connected their advanced diagnostic system and found the battery was not maintaining proper voltage, causing the computer system to store protective fault codes. The fix required: Professional diagnostic scan, Battery load test, Control unit reset with specialized VW software, System voltage stabilization check Total cost was 240€ for diagnostics, repairs, and final verification. Before suggesting more specific solutions, could you share: Battery age, Recent electrical work or modifications, Specific fault codes showing up, Any warning lights on dashboard, Starting or electrical issues before codes appeared This info would help determine if your case matches what I experienced with the ECU fault protection system.

Last service was completed at 68000km. The battery is original from factory and approximately 2.5 years old. No modifications or electrical work done recently. The fault codes are mostly related to the powertrain control module and show communication errors with various sensors. The main warning lights currently showing are check engine and electronic power control. Never had starting issues before, but noticed occasional flickering of interior lights last week. The automotive diagnostics also showed sporadic voltage drops in the system log. Would really help to know if the specialized equipment used in your case was a VW-specific system, or if other professional diagnostic tools can handle this memory lock situation. Want to avoid multiple workshop visits if possible.

Based on those symptoms, this definitely mirrors what happened with my Tiguan. The flickering interior lights are a telltale sign, I had the exact same issue before the fault memory lock activated. The ECU fault protection triggers when voltage fluctuations reach critical levels, which matches your diagnostic findings. The specialized equipment used in my case was a VW-specific diagnostic system. While other professional automotive diagnostics tools can read these codes, unlocking the fault memory protection required dealer-level software access. Regular OBD tools simply cant override these ECU security features. Given your battery age and the voltage drop indicators, I strongly suspect youre dealing with the same underlying issue. My recommendation based on direct experience: Get a proper battery load test first, Have active memory scanned with professional equipment, Request voltage monitoring across multiple operating conditions The workshop will need VW software for full ECU diagnostics and to properly reset the control modules once the battery situation is resolved. In my case, they had to follow a specific sequence to clear the protection lock without triggering additional fault codes. This type of electronic issue tends to cascade if not addressed promptly. Best to have it checked by a shop with the right diagnostic capabilities rather than risk additional control unit problems.

Thanks for sharing those details about your systems voltage patterns and fault codes. The similarities to my Tiguan case are striking. Your battery is about the same age mine was when these issues started, and the warning light combination matches perfectly. Will schedule an appointment with the dealer since they have the required control unit access. The flickering lights were definitely my first warning sign too, so catching this before it gets worse makes sense. The fault memory lock is clearly doing its job protecting the ECU from voltage-related damage. Based on what you paid, the diagnostic and repair costs seem reasonable. Really helpful to know the specialized diagnostic equipment is actually necessary and not just a way for shops to upsell services. Will update once I get the control unit errors cleared and battery situation sorted out. Thanks for walking me through your experience with this electronic fault protection system.