Normal Operation and Fault Conditions

To rotate the auxiliary temperature blend door actuator, the HVAC module supplies voltage and ground to the auxiliary temperature blend door actuator motor through the actuator motor circuits. To reverse the auxiliary temperature blend door actuator rotation, the HVAC module reverses the voltage and ground circuits.

The auxiliary temperature blend door actuator feedback resistor is supplied a 5-volt reference voltage and ground from the HVAC module. The HVAC module measures the resistance on the auxiliary temperature blend door actuator feedback circuit to determine the auxiliary temperature blend door actuator position by the position of the actuator feedback resistor wiper arm.

During an actuator calibration cycle, the HVAC module drives the auxiliary temperature blend door until the door reaches both internal stops in the HVAC case. If the auxiliary temperature blend door is temporarily obstructed or binding during a calibration cycle, the HVAC module may interpret this as the actual end of travel for the door. When this condition occurs and the HVAC module commands the actuator to its end of travel, the airflow may not be from the expected outlets.

DTC FAULT TRIGGER CONDITIONS

DTC	Description	Fault Trigger Conditions
B10B7:11	Rear Air Discharge Temperature: Circuit Short to Ground	This CMDTC sets when the HVAC senses less than expected voltage on the actuator feedback circuit, indicating a short to ground.
B10B7:15	Rear Air Discharge Temperature: Circuit Short to Battery or Open	This CMDTC sets when the HVAC senses greater than expected voltage on the actuator feedback circuit, indicating an open circuit or a short to voltage.
B11E3:11	Rear HVAC Damper Motor: Circuit Short to Ground	This CMDTC sets when the HVAC module senses a short to ground on an actuator motor circuit when voltage is applied to drive the motor.
B11E3:12	Rear HVAC Damper Motor: Circuit Short to Battery	This CMDTC sets when the HVAC module senses a short to voltage on the actuator motor circuit when ground is applied to drive the motor.
B11E3:13	Rear HVAC Damper Motor: Circuit Open	This CMDTC sets when the HVAC module senses an open on the actuator motor circuit when ground is applied to drive the motor.