VW Sharan TDI Power Loss Due to Air Temp Sensor Issue

Had almost the exact same issue with my 2018 VW Touran TDI last winter. Based on my experience with a few car repairs, this one was pretty straightforward to diagnose. The symptoms you describe match what I experienced, engine light, reduced power, and that characteristic whistling noise during acceleration. The air temperature sensor was giving incorrect readings, which made the engine management system switch to safe mode. In my case, the automotive sensor inspection revealed a loose connection at the air intake. The mechanic found that the wiring to the air temperature sensor had some wear and a damaged plug connection. The temperature fluctuation readings were all over the place because of this faulty connection. The repair took about an hour and cost me 95€, which covered the diagnostic check and fixing the connection. No parts needed replacement in my situation, just resolving the connection issue. Before suggesting anything more specific: Could you share your exact engine code and whether you notice these issues more during cold or warm weather? Also, have you had any recent work done on the air intake system? Some temperature sensors can act up seasonally, so knowing when the problem started might help pinpoint the exact cause.

Thanks for the detailed information. After my latest service at 51166km, I started noticing these exact symptoms. The airflow sensor diagnostic test confirmed similar erratic temperature readings. The mechanic mentioned the charge sensor was showing inconsistent values, affecting the air temperature measurements. When checking the connector, we found some carbon buildup around the temperature gauge housing. Would it make sense to clean the sensor connections first before considering a full replacement? The repair estimate I got was 280€ for a new sensor plus labor, which seems quite steep compared to your repair cost.

The carbon buildup you mentioned is definitely worth addressing before jumping to a full sensor replacement. In my Touran, I initially thought the engine sensor needed replacement too, but proper cleaning resolved most issues. After finding similar carbon deposits around the temperature sensor housing, a thorough cleaning of the connections and housing area dramatically improved the air temperature readings. The automotive sensor started providing consistent measurements again, eliminating those erratic temperature fluctuation patterns. The 280€ quote does seem high compared to my repair cost. While sometimes a full replacement is necessary, start with cleaning the air intake area and sensor connections. This often resolves inconsistent readings without requiring new parts. The symptoms appearing right after service is interesting, there might be a connection. During routine maintenance, disturbing the air intake components can sometimes cause connection issues or expose existing problems with the sensor setup. Try getting a second opinion focused specifically on cleaning and testing the existing sensor. Most reputable shops will perform basic diagnostics and cleaning before recommending complete replacement of engine sensor components.

Thanks for all the helpful input. Took my car to another shop today and showed them this discussion thread. Turns out you were right about trying the cleaning approach first. The mechanic cleaned the air intake system and the temperature sensor connections thoroughly. After removing all the carbon deposits, the temperature gauge started showing normal readings again. The whistling noise disappeared completely and the engine light turned off after they reset the system. Total cost was only 120€ for diagnostics, cleaning, and reset, much better than the 280€ replacement quote. Performance is back to normal and the air temperature readings are consistent now. Really glad I got that second opinion before replacing parts unnecessarily. Also learned to keep a closer eye on the air intake system during regular maintenance to prevent carbon buildup from causing these sensor issues again. Going to ask for inspection of these components during the next service interval.