VW Touran Water Sensor Issues Causing Engine Problems

Had a similar situation with my VW Tiguan (2018, gasoline). From my moderate experience with car electronics, these symptoms often point to electrical faults in the sensor connections rather than the sensor itself. The malfunction indicator kept coming on intermittently, and car diagnostics showed similar error codes. My workshop found the root cause was a damaged wiring harness connector going to the moisture sensor. The insulation had worn away, causing intermittent electrical contact. The fix involved replacing the connector and rewiring that section. Total repair time was about 2 hours, costing 95€ including parts and labor. Since then, no more engine check lights or performance issues. For a more accurate diagnosis of your situation, could you share: The specific error codes from your diagnostic scan, Whether the check light appears during specific conditions (wet weather, after car wash), If you notice any correlation between the rough engine performance and specific driving conditions This information would help determine if your issue matches the sensor testing results I experienced or if it might be something different.

Had the sensor fault checked at my last service (75121km). Car diagnostics revealed the moisture sensor was failing intermittently. The auto electronics specialist confirmed water intrusion at the connector, causing false readings and triggering the malfunction indicator. The error codes match yours exactly. I also experienced the rough running, particularly in damp conditions. My mechanic identified corrosion on the sensor pins and surrounding wiring harness. The complete repair including new moisture sensor and harness connector came to 180€. Would appreciate knowing if you noticed any improvement in fuel consumption after the fix? Mine seems slightly better since the repair.

Thanks for sharing your repair details. Yes, I noticed similar improvements after fixing the water sensor issue on my Tiguan. Fuel consumption dropped by roughly 8% once the sensor malfunction was resolved, likely because the engine management system was getting accurate readings again. The corrosion pattern you described matches what I encountered, moisture intrusion at the connector causing intermittent electrical faults. Though my repair costs were lower since only the connector needed replacement, the complete sensor replacement you had done is often the better long-term solution when corrosion is involved. Since the repair, my engine runs noticeably smoother, especially in wet conditions where the sensor fault used to trigger the malfunction indicator most frequently. The diagnostic codes haven't returned in over 8 months now. Just monitor your sensor readings for the next few services to ensure the new unit maintains proper calibration. While these electrical issues rarely recur after a proper fix, it's worth keeping an eye on the connection points during routine maintenance.

After driving another 2000km since the repair, I can confirm significant improvements in overall performance. The fuel consumption has definitely improved, seeing about 0.7L/100km better efficiency compared to when the sensor fault was active. The car diagnostics from my latest check showed all systems working normally, with no error codes related to the water sensor replacement. More importantly, the rough running issues have completely disappeared, even during the recent rainy weather when the moisture sensor gets heavy use. For 180€, the repair has proven worthwhile. The engine management system now gets accurate readings, resulting in smoother operation and better fuel economy. Both the new sensor and harness connector are holding up well with no signs of the previous corrosion issues or intermittent electrical faults. From my experience, anyone facing similar symptoms should definitely get their moisture sensor connections checked. Early intervention can prevent more extensive engine performance problems down the line.