Theory Of Operation

The HVAC Actuators contain two circuits that the HVAC Module uses to move and monitor their position. When a new HVAC Module is installed or reprogrammed, or if an actuator or door is replaced or otherwise disturbed, the Actuator open and closed positions need to be relearned. The HVAC Module counts the pulses that it takes to move the door from one stop to another. The Actuator relearn process will be aborted if any Actuator Circuit DTCs are set or the door movement is less than expected. Most of the door actuators share a common door driver circuit but each door actuator has its own unique driver circuit. Due to shared circuitry, similar Diagnostic Trouble Codes (DTCs) can set at the same time for multiple actuators depending upon the type of circuit malfunction, its location, and the direction the actuator is moving when the malfunction is present. For further information. Refer to DESCRIPTION .