B0423

Schematic:

CIRCUIT DESCRIPTION
The passenger air mix actuator is an electronic actuator stepper motor. When the air flow is cool (heater core bypass), the voltage is high. When the airflow is warm (through the heater core), the voltage is low. The IPM controls the passenger air mix actuator position to maintain the air temperature selected by the passenger.

CONDITIONS FOR RUNNING THE DTC
The ignition is turned ON.

CONDITIONS FOR SETTING THE DTC
The IPM detects the signal circuit is less than 0.09 V (5 counts) or greater than 4.88 V (250 counts).

ACTION TAKEN WHEN THE DTC SETS
^ A default value of 2.5 V (128 counts) will be used for the sensor data by the IPM.
^ The IPM will toggle the actuator between full hot and full cool in an attempt to maintain the temperature selected by the passenger.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The DTC will become history if the IPM no longer detects a failure.
^ The history DTC will clear after 50 fault free ignition cycles.
^ The DTC can be cleared with a scan tool.

TEST DESCRIPTION

Steps 1-8:

The number(s) below refer to the step number(s) on the diagnostic table.
3. Tests for the proper operation of the circuit in the high voltage range.