B0238

CIRCUIT DESCRIPTION
The mode actuator is an electronic stepper motor without a feedback circuit. It responds to voltage inputs from the HVAC control module with precalibrated non-adjustable position settings. The HVAC control module adjusts the mode actuator position to direct airflow from the outlets selected by the vehicle occupants.

CONDITIONS FOR RUNNING THE DTC
^ The ignition is turned ON.
^ DTC B1327 must not be current.

CONDITIONS FOR SETTING THE DTC
The mode door control circuit is shorted to ground or shorted to battery voltage for more than 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
Control of the mode door position will be disabled.

CONDITIONS FOR CLEARING THE DTC
^ The DTC will become history if the HVAC control module no longer detects a failure.
^ A history DTC will clear after 50 malfunction free ignition cycles
^ The HVAC control module receives the clear code command from the scan tool.

TEST DESCRIPTION

Steps 1-9:

The numbers below refer to the step numbers on the diagnostic table.
2. The mode actuator can be driven to one of two positions using the Defrost and A/C command keys on the scan tool. The scan tool displays module output as a percentage of maximum control voltage. It does not indicate true actuator or door position.
3. This step verifies that the actuator is receiving the control voltage.