Audi Q2 Parking Heater Malfunction, Fix Guide

I faced a similar heating system issue with my Audi A3 (2016, gasoline). The auxiliary heater would not engage, showing an error code, while the main car heater functioned normally during driving. The root cause turned out to be a faulty control module in the auxiliary heating system. The ventilation system itself was intact, but the electronic component that manages the parking heater function had failed. This is actually a known issue that requires specialized diagnostic equipment to properly identify. At the repair shop, they found that the control unit needed replacement, not just reprogramming. This was a serious repair that required Audi-specific diagnostic tools and expertise. The blower motor and other climate control components were working correctly, which matched the symptom of normal operation while driving. The repair process involved: Full diagnostic scan, Control module replacement, System reprogramming, Function testing While costly, this fix resolved the issue completely. For your Q2, I would recommend going directly to an Audi specialist who has experience with auxiliary heater systems, as generic shops often lack the specific diagnostic capabilities needed for this repair.

Thanks for sharing that detailed experience. That gives me hope since my Q2 shows exactly the same symptoms. The temperature sensor seems to work fine as the regular heating system functions normally while driving. Did you remember roughly how much you paid for the control module replacement? Also wondering if any other issues with the heater core or coolant leak came up since the repair was done? The dealer quoted me pretty high for diagnostics alone so trying to get an idea if I am being overcharged.

After getting my Audi checked at the specialist workshop, the auxiliary heater problem was completely fixed. The issue turned out to be a defective glow plug, not the control module as initially suspected. The repair cost came to 440 Euro, which included diagnostics and replacement. Since the repair, the heating system has worked flawlessly with no problems related to the heater core or coolant leak. The auxiliary heater now starts reliably in cold weather, and all error codes have cleared from the system. For your Q2, the diagnostic fee quote from the dealer might seem high, but proper testing of the auxiliary heater system requires specialized equipment. While my repair ended up being a glow plug rather than a control module, having an expert diagnosis helped identify the exact issue without replacing unnecessary parts.

Thanks for all the insights. I finally got my Q2 checked at a different workshop that specializes in heating systems. The auxiliary heater problem was traced to a damaged wiring harness, which was causing intermittent connection issues with the control unit. The total repair came to 380 Euro including diagnostics and parts, much less than the dealer quote. The technician showed me the frayed wiring and explained how it was affecting the parking heater function. They also checked the heater core and temperature sensor while doing the repair, confirming everything else was working properly. The ventilation system is now working perfectly, including the auxiliary heater function. No error codes have appeared since the fix was completed last week. Really glad I got a second opinion instead of paying the high dealer diagnostic fees.