Full Heat even when set to cold - servo motor fault
 

Heater flap control wasn't working. I've seen many videos on how to fix this and most people seem to buy a new unit rather than repairing the servo motor itself. It is very easy to repair:

1: Remove glove box (approx 8 screws and its out)
2: With ignition on move each of your controls to see which servo motor is not responding - easy to spot each one moving
3: Disconnect electrical plug on the suspect servo motor
4: Remove the 3 screws holding the servo motor in place and disconnect the actuator arm
5: Open up the servo motor by pushing the tabs out with a fine blade
6: Check the attached photo - you can remove the little motor and two cogs easily
7: Clean them up and use some silicone lubricant
8: Put it back together and test with either a 12v bench supply or plug it back in the car

One word of caution, make sure you either mark or take a photo of the original position of the rotation arm before disassembly....

https://cimg5.ibsrv.net/gimg/www.aud...572dee7644.jpg
Servo motor actuator arm
https://cimg1.ibsrv.net/gimg/www.aud...5d656f90aa.jpg
Opened up showing two cogs and potentiometer
https://cimg4.ibsrv.net/gimg/www.aud...eff461b552.jpg
Close up view showing motor fully and cogs.