VW Polo HVAC Sensor Failure Halts Climate Control

Had similar climate issues on a 2005 VW Golf TDI. The temperature control system showed identical symptoms, no automatic climate regulation and AC failure. Initial diagnosis pointed to sensor problems, but after inspection the real cause was a damaged wiring harness connector to the climate control module. The insulation had worn through, causing intermittent connection failures and system errors. The repair involved replacing the entire wiring harness section and recalibrating the climate control module. While not a complex fix, accessing the wiring required removing several dashboard components. Total repair time was around 4 hours at the shop. This is a known weak point in VW climate control systems from that era. The sensor itself is rarely the root cause, connection issues are more common. Having the wiring thoroughly checked before replacing any sensors can save significant diagnostic time. Would suggest getting the wiring connections inspected first, particularly around the climate control module and temperature sensors. A proper diagnostic scan can pinpoint if its truly a sensor issue or a wiring problem.

That climate control wiring fix sounds really similar to what I experienced with my 2007 Polo last winter. My temperature sensor also showed errors and the climate regulation was completely dead. It turned out the main harness connector had corroded, affecting several sensor readings. Makes me wonder if VW has some issues with their wiring quality from that period. Since getting it fixed, my climate control has worked flawlessly, but it would be helpful to know what repair costs youre looking at. Did the wiring harness repair hold up well over time? Any other sensor diagnostics needed since then?

Good to report back that it was indeed a faulty interior temperature sensor causing the climate control problems in my Golf. After taking it to the mechanic last week, they found a damaged cable connection that was disrupting the sensor readings. The repair was straightforward, just 95€ to fix the connection and get the temperature sensor working properly again. Much cheaper than replacing the entire climate control unit, which was my initial worry. The climate regulation system has been working perfectly since the fix. No more error codes or sensor issues with the automatic temperature control. This confirms what you experienced, these climate control problems often trace back to simple connection faults rather than major component failures. Looking at both our cases, it seems these sensor connection problems are quite common in VW models from that era. The original wiring has held up fine since the repair with no additional climate sensor diagnostics needed. Definitely worth checking the connections first before assuming worst-case scenarios with these temperature regulation systems.

Thanks for sharing that helpful insight about the wiring connection issues. After visiting my mechanic yesterday, they diagnosed and fixed my climate control problems in just under 3 hours. The final bill came to 150€, covering both parts and labor. The culprit was exactly what you described, corroded wiring connections affecting the HVAC sensor readings. They cleaned up the connections, replaced a section of damaged wiring, and recalibrated the climate control system. The automatic temperature regulation now works perfectly again. The mechanic mentioned these connection issues are pretty common on VW models from our era. They recommended checking the climate control wiring annually to prevent future sensor failures. Really glad I asked here first, saved me from unnecessarily replacing the entire temperature sensor unit. The repair has completely resolved my AC and climate regulation problems. No more error codes or system malfunctions. Hopefully this fix lasts as long as yours did.