VW Arteon HVAC Sensor Fault Kills Cabin Heat Output

The HVAC sensor fault you describe matches what I encountered with a 2014 VW Passat. The sunlight sensor malfunction initially presented as weak cabin heating, similar to your symptoms. The daylight sensor connection had corroded at the base, disrupting the entire HVAC system operation. The repair involved accessing the sensor unit mounted near the windshield. After testing, it turned out the sensor calibration was functioning, but the wiring harness needed replacement due to moisture damage. The connection plug showed significant corrosion at the terminals. This was not a severe mechanical issue, but leaving it unrepaired can lead to complete HVAC system malfunction. The sensor fault prevents proper temperature regulation and needs professional diagnosis. Before visiting a shop, check if the sensor area near the dashboard has visible damage or water stains. A basic inspection should cover: Sensor plug connection integrity, Wiring harness condition, Mounting bracket security, Visible corrosion signs The repair requires specialized diagnostic equipment to properly calibrate the sensor after replacement.

Thanks for sharing your Passat experience. Going through something very similar with my Arteon right now. Had the exact same symptoms with the heating performance dropping significantly. The fault detection system also flagged sensor issues in my case. Really helpful tip about checking the sensor connections, found some serious corrosion around the HVAC sensor wiring just like you described. Mind sharing what the repair ended up costing you? Also curious if you had any recurring issues with the temperature sensor system since getting it fixed? Planning to get mine looked at next week but trying to budget for it.

Got the repair done last week actually. The mechanic found the same issue we discussed, corroded connections affecting the sunlight sensor operation. Total cost was 95€ to fix the faulty cable connection, which was actually less than expected. The temperature sensor system has been working flawlessly since the repair. The HVAC performance returned to normal immediately after the fault detection system was cleared. The cabin heats up properly now, even on lower settings. The mechanic confirmed what I suspected, these sensor issues typically stem from water infiltration around the windshield area. The good news is that once the connection is properly sealed and the fault codes are cleared, the problem rarely returns. Worth noting that a proper fix includes testing the entire HVAC sensor network to ensure no other components were affected by the corrosion. In my case, the main sunlight sensor was still good, just the wiring needed attention. Based on your description, sounds like you caught it early enough to avoid more extensive damage to the temperature control system.

After dealing with this heating issue for weeks, I finally got it sorted at the shop yesterday. The mechanic found exactly what was mentioned, corroded wiring near the sunlight sensor. Turns out water had been seeping in through a small gap near the windshield seal. The repair was straightforward once they identified the problem. Cost me 120€ total, including the fault detection scan and fixing the wiring harness. The car sensor system needed a quick calibration after the repair, but now everything works perfectly. Heating performance is back to normal and the temperature stays consistent. Such a relief not having to blast the heat at maximum anymore. No error codes since the fix either. Not as expensive or complicated as I feared. Should have gotten it checked sooner instead of worrying about another bad repair experience. Thanks for helping me understand what I was dealing with before heading to the shop.