Audi Q5 Moisture Sensor Issues Hit Engine Performance

Having some experience with car diagnostics, I faced a similar sensor issue on my 2014 Audi Q3 2.0 TFSI. The moisture sensor problem showed similar symptoms, rough running and illuminated check engine light. After running car diagnostics, my workshop found that the connection between the sensor and its plug was compromised, causing faulty readings. The auto electronics examination revealed corrosion in the connector, which interfered with the signal transmission. The repair involved cleaning the connector and replacing damaged wiring sections. Total cost was 95 Euro, mainly covering labor and new connector parts. The car sensor started working properly after the fix, and the engine performance returned to normal. To provide more specific advice for your case, could you share: Current mileage, Any recent work done on the car, Whether the issue occurs more during specific conditions (cold starts, wet weather), Which specific error code the scan showed These details would help determine if your issue matches what I experienced with the moisture sensor system. Consider having a professional run a complete diagnostic scan. Sometimes what appears as a sensor issue can be related to other components in the system.

Thank you for the useful information. My mileage is currently at 67414 KM and the last service was performed just 2 months ago. The car sensor malfunction occurs mainly during cold starts, and gets worse in humid weather. I noticed the issue started right after a period of heavy rain. The error code from my scanner shows P0461, which points to a water sensor circuit malfunction. The engine also seems to hesitate more when accelerating from a stop. Would cleaning the connections first be a sensible approach before replacing the entire moisture sensor unit?

Thanks for providing those additional details. The symptoms you described match exactly what I experienced, especially the correlation with wet weather and cold starts. Given the error code P0461 and the recent rainy conditions, this strongly suggests a similar sensor fault to what I encountered. In my case, cleaning the connections initially helped but proved to be a temporary fix. The moisture sensor continued showing errors after about a week. The hesitation during acceleration you mentioned was also present in my Q3, and it turned out the faulty sensor readings were causing the ECU to run a conservative fuel mixture. Based on my experience, I recommend: 1. First attempt cleaning the sensor connections 2. Have the wiring harness checked for water intrusion 3. If problems persist, consider a full sensor replacement The complete sensor replacement on my car ended up costing 280 Euro including labor. However, the investment was worth it as it completely resolved the sensor issue and restored normal engine performance. The repair shop also applied a protective coating to prevent future corrosion. Consider getting this addressed soon, as running with sensor fault conditions can lead to poor fuel economy and potential long-term engine stress.

Thanks everyone for the detailed feedback. After inspecting the connections yesterday, I found significant corrosion around the moisture sensor wiring, which explains the erratic behavior during wet conditions. The mechanic estimated 310 Euro for a complete sensor replacement including new wiring harness and protective coating. Given how similar my symptoms are to the ones described and considering the car diagnostics results, I will proceed with the full replacement rather than just cleaning. The sensor testing clearly showed intermittent voltage readings, confirming the unit itself is failing. The ongoing poor performance and risk of engine damage make this a necessary repair. Will update once the work is completed. Hopefully this helps others who encounter similar car sensor problems with their vehicles.