Audi Q8 Hybrid Solar Sensor Causes Heat System Failures

I faced a very similar sensor fault with my Audi Q7 Hybrid from 2019. Having some experience with hybrid systems, I understood these symptoms could indicate issues with the daylight sensor which affects climate control performance. Initially, the temperature sensor readings were inconsistent, causing heating irregularities. After checking fault detection codes, my workshop discovered loose wiring connections to the sensor unit. The main issue was a damaged plug connection that caused intermittent sensor communication failures. The repair involved: 1. Full diagnostic scan 2. Testing sensor connections 3. Replacing damaged connector pins 4. Recalibrating the sensor system Total cost was 95 Euro including parts and labor. The heating system worked perfectly after the fix, and no errors returned. Before suggesting specific solutions for your Q8, could you share: The exact error codes showing up? Whether the issue occurs consistently or intermittently? If the problem started suddenly or developed gradually? Have you noticed any other electrical issues? This information would help determine if your issue matches what I experienced or if it might be a different sensor-related problem.

Last serviced 1 month ago at 37767 KM. Thanks for sharing your experience. The errors are consistent and started showing up suddenly last week. I am getting error code P0B48 which seems related to the HVAC sensor system. No other electrical issues noticed so far. The daylight sensor seems to be working fine for auto headlights, so I suspect the issue might be isolated to the climate control unit. The solar sensor readings are particularly erratic during cloudy conditions. Will try checking the connector pins as you suggested before considering a full sensor replacement.

Thanks for providing those details. Based on the P0B48 code and your description, this does sound different from my connector issue, despite similar symptoms. When I had my Q7 HVAC sensor problem fixed, the error codes were different, pointing to communication faults rather than the sensor unit itself. The fact that your auto headlights work normally while the solar sensor readings are erratic specifically during cloudy conditions suggests a faulty HVAC solar sensor unit rather than a wiring issue. These automotive sensors can deteriorate over time, affecting climate control performance. In my Q7, after the initial connector fix, I actually encountered a similar scenario 6 months later. The sunlight sensor had partially failed, causing inconsistent HVAC performance. The replacement cost was higher at 320 Euro, but it completely resolved the issue. Given your symptoms and the specific error code, you might want to: 1. Have the workshop perform a targeted test of the solar sensor unit 2. Request a comparison of sensor readings against known good values 3. Consider direct replacement if readings are out of spec The sensor fault in your case seems more component-specific than my initial wiring problem. The low mileage suggests this might be a premature failure rather than wear and tear.

As the original poster, I appreciate all these insights about the sunlight sensor issues. After comparing our cases, it seems my situation points more toward a faulty sensor unit rather than connection problems. Since my Q8 is still relatively new with low mileage, I will contact the dealer to check if this fault detection might be covered under warranty. The temperature sensor behavior during cloudy conditions is particularly concerning, and your experience with the similar automotive sensor replacement gives me a good cost estimate to consider. I will get the workshop to run those specific tests you mentioned before proceeding with any repairs. Good to know the fix brought your system back to normal operation. Will update once I have the sensor unit properly tested and know more about the exact nature of the fault.