Golf Hybrid HVAC & Sensor Failures Need Expert Fix

Had a similar issue with my 2017 Golf GTE hybrid at 145000km. The temperature sensor and sunlight sensor faults caused the same symptoms, weak HVAC performance and erratic auto climate behavior. In my case, the main problem was a damaged wiring harness connecting the automotive sensor cluster to the climate control module. The insulation had worn through, causing intermittent connection issues. The sensor calibration was also off due to the faulty connections. The repair involved: Full diagnostic scan of the HVAC system, Testing individual sensor connections, Replacing the wiring harness, Recalibrating the temperature and solar sensors, Verifying proper auto climate operation This was a moderate repair that took about 4 hours. While not a critical safety issue, leaving it unfixed can lead to complete HVAC failure and potential damage to other connected systems. Recommend having the sensor connections checked first before replacing any components. Often the wiring is the culprit rather than the sensors themselves.

Thanks for sharing your experience. That sounds exactly like what I am dealing with. I will get the wiring harness checked first. Could you remember roughly how much the repair cost in your case? Also wondering if you had any other issues pop up since getting it fixed? I am especially worried about fault detection accuracy since my car already shows unusual errors. Want to make sure I do not miss any underlying problems while fixing the sensor connections.

Great news, got the solar sensor fault completely resolved last week. The repair was much simpler and cheaper than my original case, only 95€ to fix a faulty cable connection. No error codes or HVAC issues since the repair. The fault detection system is working normally now and the temperature sensor readings are accurate. The auto climate control responds perfectly to sunlight changes. Your concern about catching underlying issues is smart, having a proper diagnostic scan done can reveal if other sensors need calibration. My earlier wiring harness issue was more extensive, but sounds like you may have caught the problem earlier. Would still recommend having them check all HVAC sensor connections while they are in there, just to prevent future problems. I have put about 5000km on the car since fixing the sensor system and everything continues working great. The climate control maintains steady temperatures and all fault detection functions are reliable.

Thanks for the input. Finally took my Golf to a trusted mechanic my colleague recommended. The diagnosis showed exactly what was discussed, faulty wiring to the daylight sensor causing the HVAC issues. Total repair came to 280€ including: Complete system diagnostic, Fixing damaged wiring near the sunlight sensor, Cleaning the sensor connections, Testing all HVAC sensor functions, Labor costs The whole job took about 2 hours. Initial testing looks good, climate control is responsive again and no more unusual error messages. The heating works properly now and adjusts correctly based on outside conditions. The mechanic showed me the worn spots in the wiring and explained how the car sensor system works together. Much better experience than my previous repair attempts. Will definitely use this shop again if any other issues come up. Really glad I asked here first and knew what to look for. Saved me from potentially replacing parts unnecessarily. The car feels like new again.