VW Touran ABS Light & Speed Sensor Failure Alert

Had the same symptoms on my 2010 VW Tiguan TSI. The speedometer fluctuations combined with ABS warnings pointed to a failing wheel speed sensor, but diagnostic testing revealed a more complex issue with the ECM and ABS control module communication. The root cause was a corroded wiring harness affecting multiple systems, the odometer readings, speedometer, and ABS functionality were all compromised. The repair required replacing the damaged wiring harness and recalibrating both the ABS module and ECM to restore proper system communication. This was definitely a serious electrical issue that needed immediate attention, as compromised ABS functionality creates major safety risks. When the system fails, it affects both traction control and emergency braking capabilities. The repair process involved: Full diagnostic scan, Wiring harness replacement, ECM and ABS module recalibration, Testing all speed sensors, Road testing to confirm fix Would recommend having it checked soon, as driving with faulty ABS can be dangerous in emergency situations. Make sure to get a proper diagnostic scan before any repairs.

Thanks for sharing your experience, really helpful as I am seeing similar dashboard warnings on my VW Touran. The ECM communication issue with corroded wiring makes total sense given my symptoms. The speedometer malfunction and sensor problems match exactly what I am experiencing. Did the fix actually solve everything long-term? Would really appreciate knowing what you ended up paying for the full repair. Planning to take mine in next week and want to have a rough cost estimate before talking to the shop.

Just wanted to update that after taking my Tiguan to the shop, the Speed signal fault was completely resolved. The transmission and ABS systems are now working flawlessly. The mechanic confirmed the diagnosis of the affected control unit being defective and needing replacement. The total repair came to 1000€, which covered the new control unit, programming, and testing. This was actually cheaper than initially expected given the complexity of the electronic systems involved. My dashboard is now clear of warning lights and the speedometer readings are consistently accurate. The ABS input signals are properly registering from all wheels, which has restored normal braking and traction performance. Been about 6 months since the repair and everything is still working perfectly, no more erratic odometer behavior or safety system glitches. While it was a significant repair cost, having reliable ABS and accurate speed readings was worth the investment for safety reasons.

Thanks for the detailed responses. Just wanted to share how my VW Touran repair went. Took it to a certified shop last week and they ran a full diagnostic scan which confirmed the faulty wiring and ECM communication issues. The mechanic found extensive corrosion in the ABS wiring harness behind the wheel well, explaining the unusual traction losses and warning lights. The repair involved replacing the damaged harness section and recalibrating both the ABS module and ECM. Total cost came to 850€ including parts and labor. The input signals from all speed sensors are now working correctly. My speedometer and odometer are both showing accurate readings again. Most importantly, the ABS system is functioning properly with no more warning lights. The repair was definitely worth it for the safety aspect alone. Really glad I got it fixed before winter when reliable ABS becomes even more critical. The shop did great work and the price seemed fair compared to what others paid for similar repairs.