Actuator, Blend Door: Operation

The two blend door actuators are connected to the A/C heater module through the vehicle electrical system by dedicated two-wire lead and connectors of the HVAC wire harness. The blend door actuators can move the blend-air doors in two directions. When the A/C heater module pulls the voltage on one side of the motor connection high and the other connection low, the blend-air door will move in one direction. When the A/C heater module reverses the polarity of the voltage to the motor, the blend-air door moves in the opposite direction.

When the A/C heater module makes the voltage to both connections high or both connections low, the blend-air doors stops and will not move. The A/C heater module uses a pulse-count positioning system to monitor the operation and relative position of the blend door actuators and the blend-air doors. The A/C heater module learns the blend-air doors stop positions during the calibration procedure and will store a Diagnostic Trouble Code (DTC) for any problems it detects in the blend door actuator circuits.

The blend door actuators are diagnosed using a scan tool. Refer to DIAGNOSTIC CODE INDEX .

The blend door actuators cannot be adjusted or repaired and must be replaced if inoperative or damaged.