Audi Q5 HVAC Sensor Failure Causes Total Climate Shutdown

The climate regulation issues with failing HVAC sensors are common on Audi models. Had similar temperature reading problems on my 2014 A4 2.0T, where the climate control system stopped responding completely. The root cause was indeed a faulty temperature sensor, but also discovered corroded wiring connections to the HVAC control module. The sensor issues affected both the auto temperature function and manual AC operation. The repair involved: Testing the HVAC sensor circuit, Replacing the main temperature sensor, Repairing damaged wire connections, Clearing stored fault codes, Testing climate system operation This was a moderate repair job, requiring around 3-4 hours of diagnostic and repair time. The climate issues were serious enough to affect overall driving comfort but not vehicle operation. Without proper sensor input, the climate control system defaults to a fail-safe mode. Most important is having a proper diagnostic scan first, as similar symptoms can come from different component failures in the climate regulation system. Worth getting it checked soon to prevent additional HVAC system damage.

Thanks for sharing your A4 experience. I am having almost identical climate issues with my Q5. Good to know about checking those wire connections, will definitely mention that to the shop when I take it in for the sensor diagnostics. The sensor problems in my Q5 are really starting to affect daily driving now that temperatures are changing. Been meaning to ask, do you remember roughly what you paid for the full HVAC sensor repair? Also, has your climate control system been working properly since the fix?

Good news, after mentioning the cable connections you brought up, the mechanic found a similar issue with my Q5. The whole climate control system is now working perfectly since the repair. It turned out the interior temperature sensor had a faulty connection that was causing the climate regulation problems. The fix was actually simpler and cheaper than expected, just 95 Euro to repair the defective plug connection to the sensor. No need for complete sensor replacement in my case. The sensor diagnostics showed it was functioning, but the signal wasnt reaching the climate control module properly. The auto temperature feature and AC are now responding correctly, and the warning light is gone. It makes a huge difference having proper climate regulation again, especially during temperature changes. The sensor issues were completely resolved through this repair, which took less than 2 hours total. My experience suggests having the wiring connections checked first before assuming you need a full temperature sensor replacement. A proper diagnostic scan can save money by pinpointing exactly where the climate control system is failing.

Thanks everyone for the helpful feedback on the HVAC sensor issues. Took my Q5 to the shop yesterday and wanted to share my experience. The mechanic found corroded wiring at the temperature sensor connection, just like you mentioned. Total repair cost was 180 Euro, more than a simple wire fix but way less than I feared for a full sensor replacement. They cleaned the connections, repaired some damaged wires, and recalibrated the climate control system. The whole job took about 2.5 hours. My climate issues are now completely fixed, the auto temperature control works perfectly and the AC blows nice and cold again. No more warning lights on the dash either. Really glad I mentioned the wiring issue you brought up. The mechanic said catching it early prevented further damage to the HVAC system that could have been much more expensive. The temperature reading is now accurate and all climate functions are working as they should. Much better experience this time compared to my last mechanic visit. Thanks again for helping me understand what to look for with these sensor issues.