Turn the controller to full cold. Pull the fuse for the HVAC wait 1 minute and replace. Turn the Key on Engine off....DO NOT touch any control until the system goes through it's learning process about 1 minute. Now start the vehicle. Does it work now?My heater and air con have both stopped working. The fans still blow and the ac pump kicks in just neither work. I have changed the display unit but fault remains. Please help.