B0239 Possible Causes
- Faulty Defrost Actuator
- Defrost Actuator harness is open or shorted
- Defrost Actuator circuit poor electrical connection
- Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module
How do I fix code B0239?
Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.Cost of diagnosing the B0239 code
Labor: 1.0
The cost of diagnosing the B0239 code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B0239 Meaning
The Heating, Ventilation, and Air Conditioning (HVAC) Control Module controls the HVAC actuators to regulate the airflow and temperature through the HVAC system. The actuators are 2 wire, bi-directional electric motors that share the same common control circuit. When the operator adjusts the actuators, the control module can only operate one actuator at a time due to the shared common control circuit. The control circuits use either a 0 or 12-volt value to co-ordinate the actuator movement. The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction.The HVAC control module determines the door position by counting motor pulses on one of the control circuits. The HVAC control module converts the pulses to counts with a range of 0-255 counts.
When a calibration or recalibration procedure is performed, the HVAC control module calculates the door travel range. The HVAC control module compares the total number of pulses to calibrated limits. If the total pulse count is less than or equal to the maximum calibrated limited and more that or equal to the minimum calibrated limit, then the calibration is considered successful.
B0239 More Information
Need more information on how to fix the B0239 code?Get Access to Factory Service Manuals
Information for specific makes
- B0239 BUICK Air Flow Control 1 Circuit Performance
- B0239 CADILLAC Air Flow Control 1 Circuit Performance
- B0239 CHEVROLET Air Flow Control 1 Circuit Performance
- B0239 GMC Air Flow Control 1 Circuit Performance