AutoCodes – Chevrolet – B374A:05 Chevrolet

B374A:05 Chevrolet 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 Chevrolet 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.

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Code Popularity 2,392

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B374A:05 Chevrolet Description

Doors in the Heating, Ventilation, and Air Conditioning (HVAC) case assembly are used to control airflow. The HVAC control module operates the doors using actuators, with one actuator being used for each door. The system has the following air control doors and associated actuators: mode, left and right temperature, and recirculation. When equipped with auxiliary HVAC controls 2 additional actuators are added for auxiliary (rear) mode and temperature.
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.

OBDII Code B374A:05 Chevrolet - Air Flow Control Position Feedback Circuit Short To Battery Or Open - AutoCodes.com — B374A:05 Chevrolet Code - Air Flow Control Position Feedback Circuit Short To Battery Or Open

What does this mean?

What are the Possible Causes of the DTC B374A:05 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:05 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:05 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.

Need more information about the B374A:05 Chevrolet code?

Need more information on how to fix the B374A:05 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B374A:05 Chevrolet code diagnosed by a professional: Find a repair shop in your area

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

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B374A:05 Chevrolet Code

1. What does the OBDII code B374A:05 mean on a Chevrolet?

The code B374A:05 indicates an issue with the air flow control position feedback circuit, specifically a short to the battery or an open circuit.

2. What are the common symptoms of the B374A:05 code in a Chevrolet?

Symptoms can include erratic or non-functional HVAC airflow direction control, unusual noises from the HVAC system, or the HVAC system stuck in one airflow mode.

3. What causes the B374A:05 code to appear in a Chevrolet?

Common causes include damaged wiring, a faulty air flow control actuator, a defective position sensor, or a short circuit in the feedback circuit.

4. Can a faulty actuator cause the B374A:05 code?

Yes, a malfunctioning air flow control actuator can fail to provide proper feedback, triggering this code.

5. How can I diagnose the B374A:05 code on my Chevrolet?

Start by visually inspecting the wiring and connectors for damage, check for continuity in the circuit, and test the air flow control actuator for proper operation.

6. Is it safe to drive with the B374A:05 code on a Chevrolet?

Yes, itâ€™s generally safe to drive, but the HVAC system may not function properly, which could lead to discomfort or reduced visibility if defrost mode is affected.

7. How do I fix the B374A:05 code in my Chevrolet?

Repairs may involve replacing damaged wiring, repairing connectors, or replacing a faulty air flow control actuator or position sensor.

8. How much does it cost to fix the B374A:05 code on a Chevrolet?

The cost depends on the specific repairs needed, but actuator replacement typically ranges between $150 and $400, including parts and labor.

9. Can clearing the B374A:05 code fix the problem?

Clearing the code may temporarily reset the system, but it wonâ€™t fix the underlying issue causing the code to appear.

10. Do I need a professional mechanic to fix the B374A:05 code?

While some DIYers can handle basic wiring inspections, diagnosing and repairing the HVAC system often requires specialized tools and expertise, so consulting a mechanic is recommended.