B374A:05 Code - Air Flow Control Position Feedback Circuit Short To Battery Or Open
Quick Answer
Doors in the Heating, Ventilation, and Air Conditioning (HVAC) case assembly are used to control airflow. Common causes include Faulty Mode Actuator, Mode Actuator harness is open or shorted, Mode Actuator circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- B374A:05 indicates Air Flow Control Position Feedback Circuit Short To Battery Or Open.
- Common causes
- Common causes include Faulty Mode Actuator, Mode Actuator harness is open or shorted, Mode Actuator circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code B374A:05 Description
Each actuator used in the system is a 5-wire bi-directional electric motor that incorporates a feedback potentiometer. The five circuits are low reference, 5 V reference, actuator position signal, and two control circuits. The control circuits use either ground or 12 V value to coordinate the actuator movement. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 V. The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction.
When the actuator shaft rotates, the potentiometer's sliding contact changes the door position signal between 0-5 V. The HVAC control module converts the voltage signal to counts. The total range of the counts is 0-1024, with an operating range between 20-1000. The actual operating range of an actuator is determined during calibration. During calibration, the actuator is moved through its full range of travel, and the module stores the minimum and maximum value. Based on the desired system operation, the module sets a commanded, or targeted, value for the actuators. The control circuits are operated to move the door to the required position, and the changing position signal is sent to the module. Once the actual position signal and the commanded value are the same, the module ceases operating the control circuits and the actuator (and door) remains in the desired position.
The Diagnostic Trouble Code (DTC) will be set when the HVAC control module detects the sensor signal out of range. The signal voltage is greater than 4.9 V for more than 50 ms.
What are the Possible Causes of the DTC B374A:05?
- Faulty Mode Actuator
- Mode Actuator harness is open or shorted
- Mode Actuator circuit poor electrical connection
- Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module
How to Fix the DTC B374A:05?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the B374A:05 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- B374A:05 Buick — Air Flow Control Position Feedback Circuit Short To Battery Or Open
- B374A:05 Cadillac — Air Flow Control Position Feedback Circuit Short To Battery Or Open
- B374A:05 Chevrolet — Air Flow Control Position Feedback Circuit Short To Battery Or Open
- B374A:05 GMC — Air Flow Control Position Feedback Circuit Short To Battery Or Open
Frequently Asked Questions about B374A:05 Code
What does OBDII code B374A:05 indicate?
Code B374A:05 signifies an issue with the Air Flow Control Position Feedback Circuit, specifically a short to the battery or an open circuit.
What are the common symptoms of code B374A:05?
Symptoms may include reduced or irregular airflow from the HVAC system, inconsistent temperature control, or a non-responsive airflow mode.
What causes code B374A:05?
This code can be caused by a damaged wiring harness, a faulty air flow control actuator, a defective sensor, or corrosion in the circuit.
How can I diagnose code B374A:05?
Start by inspecting the wiring and connectors for damage or corrosion. Use a multimeter to test for continuity and check for shorts in the circuit.
Can a short to battery damage other components related to code B374A:05?
Yes, a short to the battery can potentially damage the air flow control actuator or other electrical components in the HVAC system.
Is it safe to drive with code B374A:05?
Yes, but your HVAC system may not function properly, which could affect cabin comfort in extreme weather conditions.
How do I fix code B374A:05?
Repair or replace damaged wiring, connectors, or the air flow control actuator. Clear the code afterward to verify the fix.
Can a faulty HVAC control module trigger code B374A:05?
Yes, if the HVAC control module fails to send or interpret signals properly, it can trigger this code.
Can the code B374A:05 be cleared without repairs?
Clearing the code without addressing the underlying issue may temporarily remove the error, but the problem will likely return.
How much does it cost to repair code B374A:05?
Repair costs can vary depending on the root cause, ranging from a simple wiring fix to actuator replacement, typically costing $100 to $500.
Discuss the causes and fixes for B374A:05 OBDII Code
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