Audi A6 Auxiliary Heater Complete System Failure Fix

The heating system failure you describe matches what I experienced with my 2015 Audi A4 2.0T. The complete shutdown of the auxiliary heater often points to either a failed control module or a blower motor malfunction. In my case, the car heater control unit displayed a similar error message. The diagnosis revealed two issues: a faulty blower motor resistor and a coolant leak in the auxiliary heating circuit. The coolant leak was causing the system to shut down as a protective measure. This is typically a serious issue that requires professional attention since the auxiliary heater is integrated with multiple vehicle systems. The repair involved: Complete diagnostic scan, Blower motor assembly inspection, Testing of all heating system components, Replacement of damaged components, System reprogramming The heating system needed a full day at the shop to fix. This isnt a repair you can postpone, especially during cold weather, as it can affect the overall engine temperature management. Consider having a specialized Audi technician check the auxiliary heating circuit and control module. These symptoms often indicate more than just a simple sensor issue.

Thanks for sharing that detailed insight on the auxiliary heater problem. I had almost identical issues with my A6, complete system shutdown and error messages in the heat control unit. The mechanics found problems with the temperature sensor and a small coolant leak near the heater core. The ventilation system also needed some attention during the fix. Would you mind sharing what the total repair cost was in your case? Just wondering how it compares, and if youve had any other heating-related problems since getting it fixed?

After visiting the mechanic, my auxiliary heater is working perfectly now. The main issue turned out to be a defective glow plug, which was causing the complete system shutdown. The total repair came to 440 Euro, including diagnostics and parts. The ventilation system and heat control unit were thoroughly checked during the repair, but fortunately no additional problems were found. The coolant leak I mentioned earlier was minor and fixed with a simple seal replacement included in the total cost. Since the repair three months ago, the heating system has been functioning flawlessly. No error messages, and the auxiliary heater activates immediately when needed. The blower motor is also running smoothly with no unusual noises. This kind of repair really needs professional attention, glad I didnt try any DIY solutions. The diagnostic equipment they used detected the glow plug issue right away, saving time on unnecessary parts replacement.

Thanks everyone for the helpful responses. I finally got my car back from the shop yesterday and wanted to share how it went. The mechanic found a faulty temperature sensor and a small coolant leak that was causing the auxiliary heater problems. The repair took about 6 hours total. They had to drain the system, replace the sensor, fix the coolant leak, and recalibrate the heat control unit. Total cost came to 380 Euro, which included a full system diagnostic and pressure testing. The car heater is working perfectly now, no more error messages and the auxiliary heating kicks in right away. The blower motor is also much quieter than before. Really glad I went to a proper shop for this fix rather than attempting any quick solutions myself. Just wanted to update everyone who helped. Thanks again for pointing me in the right direction with this issue.