B0233

DTC B0233

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






Circuit Description

The mode actuator is an electronic device that incorporates a stepper motor and feedback potentiometer. The HVAC control module controls the mode door position by sending a control signal to the actuator. The signal value is dependent upon the desired mode selected by the vehicle occupants. As the actuator moves, the potentiometer produces the actual door position signal that is sent to the HVAC control module. The HVAC control module continues to command the actuator to move until the desired and actual values are equal. The door directs airflow through the outlets as selected by the vehicles occupants.

The HVAC control module commands the actuator through it's full range. The HVAC control module stores the learned minimum and maximum position values. The travel range value is calculated by subtracting the minimum and maximum position values. Then the HVAC control module compares the travel range, minimum and maximum values to calibrated value ranges. If the travel range value is less than or equal to the maximum calibrated limit and greater than or equal to the minimum calibrated limit, then the calibration is considered successful. The HVAC control module continuously compares the actual actuator position to the calibrated minimum and maximum position values.

DTC Descriptor

This diagnostic procedure supports the following DTC:

B0233 Air Flow Control Circuit

Conditions for Running the DTC

* The ignition is ON.
* Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

* Mode actuator position signal is less than 5 counts.
* Mode actuator position signal is more than 194 counts.
* The mode actuators total travel range is less than or greater than the calibrated limits.

Action Taken When the DTC Sets

* The DTC is stored in DTC information.
* The HVAC control module will continue to make use of whatever travel range is still available.

Conditions for Clearing the DTC

* If the HVAC control no longer detects a failure, then the DTC will become history.
* The history DTC will clear after 50 ignition cycles without a failure.
* The DTC can be cleared with a scan tool.

Diagnostic Aids

* A damaged or broken mode door and or actuator can cause this DTC to set.
* If the Mode actuator travels beyond it's calibrated limits the DTC will set.

Test

Step 1 - Step 9:

Step 10 - Step 15: