Pinpoint Test K : The Air Inlet Door Is Inoperative - EATC: Notes

Refer to Automatic Climate Control System , for schematic and connector information.

Normal Operation and Fault Conditions 

To rotate the air inlet door actuator, the HVAC control module supplies voltage and ground to the air inlet door actuator through the door actuator motor circuits. To reverse the air inlet door actuator rotation, the HVAC control module reverses the voltage and ground circuits.

The air inlet door actuator feedback resistors are supplied a ground from the HVAC control module by the air inlet door actuator return circuits and a 5-volt reference voltage on the air inlet door actuator reference circuits. The HVAC control module reads the voltage on the air inlet door actuator feedback circuits to determine the air inlet door actuator position by the position of the actuator feedback resistor wiper arm.

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

In FLOOR and FLOOR/DEFROST modes, the RECIRC request will time-out after 5 minutes and return to fresh air mode. RECIRC mode can be selected again after the time-out.

DTC Fault Trigger Conditions 

Possible Sources 

• Wiring, terminals or connectors
• Air inlet mode door actuator
• HVAC control module
• Stuck or bound linkage or door