A5 Heating Failure Linked to Faulty Sunlight Sensor

A similar issue occurred with my 2019 Audi A4. The HVAC sensor malfunction caused inadequate heating control, showing comparable symptoms. The sunlight sensor and daylight sensor were functioning correctly, but the main HVAC control module had a loose connection. The fault detection system initially pointed to the sensors, but after proper diagnostics, the issue was traced to corroded pins in the main connector. The heating problems were resolved by cleaning the connection points and replacing the damaged connector housing. This type of problem typically requires professional diagnosis with specialized equipment to properly test the HVAC sensor network. While not a severe mechanical issue, it can affect comfort and proper defrosting function, which is a safety concern. Key signs to discuss with your mechanic: When the malfunction started, Whether the issue is constant or intermittent, If the system responds to manual temperature adjustments, Whether the blower motor functions normally, If error codes are consistent or unusual The connector issue could be similar in your A5, as this generation of Audi uses comparable HVAC architecture. Request a full system diagnostic before any parts replacement.

Thanks for your detailed response about the HVAC issues. It turns out my A5 had a similar connector problem, and the temperature sensor also needed recalibration. The mechanic found corrosion in the same area you mentioned. Curious how much you ended up paying for your repair? Also, have you experienced any other sensor fault issues since getting it fixed?

Thanks for asking about the repair costs. After getting my A5 fixed, I paid 95 Euro for repairing the faulty cable connection at the solar sensor unit. The price included cleaning the corroded parts and securing the plug connection properly. Since the repair, the HVAC system has worked flawlessly, with no temperature sensor issues or fault codes reappearing. The sunlight sensor now correctly adjusts the climate control based on solar intensity, which makes a noticeable difference in comfort. The investment was worth it, especially considering how crucial proper heating is. The key was finding a mechanic who properly diagnosed the car sensor network rather than just replacing parts. Regular checks of sensor connections during maintenance can prevent similar issues from developing.

Finally got my A5 fixed last week. Found a new mechanic through a local car forum who specializes in sensor diagnostics. They immediately spotted the corroded connector and performed a thorough temperature sensor calibration. The whole repair came to 120 Euro, including a complete HVAC system check. The heating works perfectly now, way better than before. They showed me the corroded parts and explained how the sunlight sensor impacts the whole system. Really glad I didnt just replace unusual parts like my old mechanic suggested. The new shop even gave me some tips about preventing future sensor issues. Turns out these connector problems are pretty common in our model. For anyone else facing similar issues, definitely get a proper diagnosis instead of guessing. The right mechanic makes all the difference.