AutoCodes - Generic - B0239

B0239 Code - Air Flow Control 1 Circuit Performance

Repair Importance Level: 1/3
Repair Difficulty Level: 2/3
Table of contents

|B0239 code 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 the B0239 code?

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's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

|What are B0239 code possible symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

|B0239 code description

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.
OBDII Code B0239 - Air Flow Control 1 Circuit Performance -

|Need more information with the B0239 code?

Need more information on how to fix the B0239 code?
Get Access to Factory Service Manuals

|B0239 code information for specific makes

|Need help with a B0239 code?

Get the B0239 code diagnosed by a professional: Find a repair shop in your area

|B0239 code comments

Help us improve Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the B0239 code? Have you replaced any parts?
Any information is appreciated. Thanks
Top ⇧
Repair Importance Level: 1
1=Low 2=Medium 3=High What is this?
Repair Difficulty Level: 2
1=Easy 2=Moderate 3=Hard What is this?