HVAC Controls Intermittently Inoperative or Improperly Responding (Reset HVAC Controller)

Some customers may comment that the HVAC controller may have become intermittently inoperative or erratic in operation. In most all cases, the HVAC controller will function normally when the vehicle is examined by the technician. Additional comments may include a variance in the air temperature from driver to passenger side air vents.

The customer may be turning the temperature knob from warm to cool or from cool to warm very rapidly. Under certain conditions, if the temperature knob is rotated very quickly, it may exceed the ability of the HVAC controller to interpret the desired action.

Cycling the key to the off position will power off the HVAC controller and reset it, restoring normal function to the HVAC system on the next vehicle start. Instruct the customer that this is a normal function of the unit and that no repairs are necessary.

You may want to provide the customer with a copy of this bulletin so that if the condition occurs in the future, the customer will not need to return to the dealership.