B374A:02 Chevrolet Code - Air Flow Control Position Feedback Circuit Short To Ground
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:02 Chevrolet indicates Air Flow Control Position Feedback Circuit Short To Ground.
- 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:02 Chevrolet 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:02 Chevrolet?
- 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:02 Chevrolet?
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:02 Chevrolet 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 Chevrolet Models
- B374A 2014 Chevrolet Silverado — Air Flow Control Position Feedback Circuit
- B374A 2015 Chevrolet Silverado — Air Flow Control Position Feedback Circuit
- B374A 2016 Chevrolet Silverado — Air Flow Control Position Feedback Circuit
- B374A 2017 Chevrolet Silverado — Air Flow Control Position Feedback Circuit
- B374A 2018 Chevrolet Silverado — Air Flow Control Position Feedback Circuit
Frequently Asked Questions about B374A:02 Chevrolet Code
1. What does OBDII code B374A:02 mean on a Chevrolet?
B374A:02 indicates an issue with the air flow control position feedback circuit, specifically a short to ground.
2. What are the symptoms of code B374A:02 in a Chevrolet?
Common symptoms include improper HVAC airflow, inability to change vent positions, and possible unusual noises from the HVAC system.
3. What causes the B374A:02 code to appear?
This code is typically caused by damaged or shorted wiring, a faulty actuator, or a malfunctioning HVAC control module.
4. Can I still drive my Chevrolet with the B374A:02 code?
Yes, but the HVAC system may not function properly, which could affect comfort or visibility if the defroster is impacted.
5. How do I diagnose the B374A:02 code in my Chevrolet?
Start by inspecting the wiring and connections for the air flow control circuit, then test the actuator and HVAC control module for faults.
6. What tools are needed to fix the B374A:02 code?
You’ll likely need a multimeter, an OBDII scanner, and possibly a repair manual for your specific Chevrolet model.
7. How much does it cost to repair a B374A:02 code?
Repair costs can vary depending on the root cause, but replacing an actuator or repairing wiring typically ranges from $150 to $400.
8. Can a faulty HVAC actuator trigger the B374A:02 code?
Yes, a malfunctioning HVAC actuator is a common cause of this code.
9. Is the B374A:02 code covered under warranty?
It depends on your warranty coverage and the age of your vehicle. Check with your dealership for details.
10. What happens if I ignore the B374A:02 code?
Ignoring the code may lead to continued HVAC system issues, such as reduced comfort or visibility problems if the defroster fails.
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