Heating/cooling door blend?

2015 AUDI A3
127,000 MILES • 1.8L • 4 CYL • TURBO • 2WD • AUTOMATIC
Avatar
BHAMDOC1973
  • MEMBER
  • 2,008 POSTS
No heat from vents. Scanned it and found these codes. Battery was weak and still is a bit, may replace it, but it still starts every time. Deleted the codes and got heat. When I went to start it, this afternoon I got the same issue, cold air from vents. Where is this door and how to replace it, please? After deleting all the codes only the B109171 remained.
Nov 27, 2023 at 12:58 PM
Advertisement
Avatar
BHAMDOC1973
  • MEMBER
  • 2,008 POSTS
After deleting all the codes only the B109171 remained.
Nov 27, 2023 at 3:06 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,872 POSTS
This car has a temperature blend door for both right and left sides and it has a main temperature blend door actuator so if the heat is not available on both sides here is the actuator that needs to be replaced. Clear the codes again once the part has been replaced. Check out the images (below). Let us know how it goes.
Nov 27, 2023 at 4:41 PM
Advertisement
Avatar
BHAMDOC1973
  • MEMBER
  • 2,008 POSTS
There is one actuator on the left side which can easily be seen once I remove the knee airbag. I removed the 2 screws on that one and removed it, turned the door by hand and it moves, but heat did not come through vents still cold air. The actuator moves when I move the knob between cold and hot. So, I am thinking there is another one, is there one that is way up in there that controls heat? but I also played with another wheel way up that I cannot reach and then deleted code and got heat. The next day the same thing, cold air. Pulled it in garage to start taking things apart and then I got heat, so I don't know which actuator is which. If the one am playing with controls heat/cool not sure why the air temp not changing when I turn the knob. even if I move the door by hand temp does not change. Very strange.
Nov 29, 2023 at 3:25 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,872 POSTS
Yes, there are three actuators for heat one for main heat and two more for controlling heat to both drivers and passenger sides. The one I mentioned above is for the main control, here are the location of the other temperature control actuator so can see. Check out the images (below). Please let us know what happens.
Nov 30, 2023 at 10:42 AM