Join my channel on Instagram as @manishcartechnology. Install the app to follow my photos a 0:00 / 7:50 How to fix Audi A6 Climate Control (HVAC, Heater unit). WheelsAndMotors 40.5K subscribers Subscribe Subscribed Share 314K views 10 years ago Attention! Another way of cleaning it - Jul 30, 2021. #2. christopher barnes said: Hi guys, noticed my heater blower wasnt working, all direction and heat ok. No a/c. I tested the fan using a 12v supply which was fine so i then lazily ordered the heater resistor thinking that this was the fault. I scanned with vcds it shows this fault code: 02071 - Local Databus. 012 - Electrical Fault in Circuit. Freeze Frame: Fault Status: 01101100. Fault Priority: 3. Fault Frequency: 1. I checked all fuses and wires,also replaced the blower and module still the same. I guess it can be a Climatronic fault. 02071 Audi A6 with no heater blower. I walk through my diagnostic thought process on this A6 logging 02071 communication fault with no heater blower more. Audi A6 models built from 2005 to 2007 have be known for having an issue with its pump valve unit; in fact, a TSB ( 2013833/5) was issued, recommending replacement of the old unit with a newly updated model. The problem occurs when the pump valve becomes blocked with engine debris. Audi A6 - (Yauhen_D / Shutterstock) The most common causes for Audi A6 AC not blowing hard enough are clogged cabin air filter, dirty evaporator coil, and frozen evaporator coil due to low refrigerant. Less common causes are dirty or sluggish blower motor and faulty mode door actuator. TbRUx.