Faulty Temp Sensor Wreaks Havoc on E-tron Systems

I experienced nearly identical issues with my 2019 Q4 e-tron Sportback last winter. Having some experience with electric vehicle maintenance, I suspected a temperature sensor problem right away when multiple temperature-dependent systems started failing simultaneously. The car temperature sensor was indeed the culprit. The issue turned out to be a loose connection at the vehicle temperature sensor plug, which was causing intermittent failures in temperature monitoring. The workshop performed a complete diagnostic check and found that water had gotten into the connector, causing corrosion. The fix was straightforward, they cleaned the connection points and replaced the damaged wiring. Total cost was 95 Euro including diagnostic time. Since the repair, all temperature-dependent systems have worked perfectly, with accurate temperature gauge readings. What specific error codes is your car showing? Would be helpful to know if theyre similar to what I encountered. Also, when did you first notice these issues? Temperature sensor problems often start gradually before multiple systems are affected. To properly diagnose this, could you share: The exact error codes from diagnostics, Whether the temperature reading on your dash fluctuates or shows incorrect values, If the issues occur more frequently in specific weather conditions, The maintenance history of your temperature monitoring system

Last service done at 40000KM covered basic maintenance, but this temperature sensor malfunction started recently. Getting error codes P0072 and P0073 in the diagnostic readout. Previously had zero issues with temperature-dependent systems until about 2 weeks ago. Looking at the temperature readings, the gauge shows -40C constantly, even on warm days, which seems to confirm sensor diagnostics pointing to a malfunction. Seems most temperature-related functions are affected regardless of weather conditions, suggesting a complete sensor failure rather than an intermittent issue. Appreciate the detailed info about the connector issue. Makes me wonder if water exposure could be the root cause here too, especially since the spraynozzle system was among the first to act up. Will get it checked by a workshop, but your response helps narrow down the likely culprit to the temperature sensor replacement area.

Thanks for those additional details. The constant -40C reading combined with error codes P0072/P0073 is exactly what I saw before my sensor diagnostics confirmed a complete outside temperature sensor failure. These codes specifically indicate an ambient air temperature sensor circuit that is either low or high, matching the symptoms perfectly. In my case, the spray nozzles acting up was also the first sign something was wrong with the vehicle temperature sensor. The constant -40C reading is a clear indicator of sensor malfunction, as this is typically the default value when the car temperature sensor stops communicating with the control unit. Since your symptoms mirror mine so closely, Id bet on the same root cause. The workshop will likely need to check the wiring harness connection points first, as water infiltration is a common issue with these sensors. My repair involved both cleaning corroded contacts and sensor replacement since the original unit was damaged beyond repair. The good news is that once fixed, all temperature-dependent systems should return to normal operation. You probably wont need any special calibration process, the new sensor should work right away once properly connected. The repair should be relatively straightforward for any shop familiar with sensor diagnostics on these models.

Thanks for the detailed response. Getting error codes P0072 and P0073 in the diagnostic readout. Previously had zero issues with temperature-dependent systems until about 2 weeks ago. Looking at the temperature gauge, it shows -40C constantly, even on warm days, which seems to confirm my suspicions about the outside temperature sensor being faulty. Most temperature-related functions are affected regardless of weather conditions, suggesting a complete sensor failure rather than an intermittent issue. Based on your experience with similar vehicle temperature sensor problems, I think getting the entire sensor replaced might be the best route, especially since there seems to be a total failure rather than just connection issues. Did you need any special temperature sensor calibration after your repair was done? Since my last service at 40000KM only covered basic maintenance, Im planning to have the workshop do a full diagnostic check of the temperature monitoring system while theyre at it. Really appreciate the info about checking for water damage, will definitely mention that when I bring it in.