OPERATION

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

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

The rear blend door actuator is diagnosed using a scan tool (refer to 24 - HEATING & AIR CONDITIONING - DIAGNOSIS AND TESTING - HEATING AND A/C SYSTEMS and to 24 - HVAC Electrical Diagnostics for more information).

The rear blend door actuator cannot be adjusted or repaired and must be replaced if found inoperative or damaged.