AutoCodes – GMC – B374A 2016 GMC Sierra

B374A 2016 GMC Sierra Code - Air Flow Control Position Feedback Circuit

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 2016 GMC Sierra indicates Air Flow Control Position Feedback Circuit.
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 267

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 2016 GMC Sierra 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.

OBDII Code B374A 2016 GMC Sierra - Air Flow Control Position Feedback Circuit - AutoCodes.com — B374A 2016 GMC Sierra Code - Air Flow Control Position Feedback Circuit

What does this mean?

What are the Possible Causes of the DTC B374A 2016 GMC Sierra?

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 2016 GMC Sierra?

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 2016 GMC Sierra 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 2016 GMC Sierra code?

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Need Help with the Code?

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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 2016 GMC Sierra Code

1. What are the common symptoms of OBDII code B374A in a 2016 GMC Sierra related to the Air Flow Control Position Feedback Circuit?

- Common symptoms include poor engine performance, reduced fuel efficiency, and potential stalling or rough idling.

2. What are the possible causes of OBDII code B374A in a 2016 GMC Sierra?

- Possible causes could be a faulty air flow sensor, damaged wiring or connectors in the air flow control circuit, or a malfunctioning electronic control module.

3. How can I diagnose the issue related to the Air Flow Control Position Feedback Circuit in a 2016 GMC Sierra?

- Diagnosing the issue may involve using an OBDII scanner to read the specific code, checking the air flow sensor for proper operation, and inspecting the wiring and connectors for any visible damage.

4. Can I continue driving my 2016 GMC Sierra with OBDII code B374A related to the Air Flow Control Position Feedback Circuit?

- It is not recommended to continue driving the vehicle with this code as it can lead to further damage and potential safety hazards. It's best to address the issue promptly.

5. How can I repair OBDII code B374A in my 2016 GMC Sierra myself?

- Repairing this code may involve replacing the faulty air flow sensor, repairing or replacing damaged wiring or connectors, or resetting the electronic control module. If you're unsure, it's best to consult a professional mechanic.

6. Will resetting the OBDII code B374A in a 2016 GMC Sierra fix the issue permanently?

- Resetting the code may temporarily clear the warning, but if the underlying issue causing the code is not addressed, it is likely to reappear. Proper diagnosis and repair are necessary for a permanent solution.

7. Is it safe to drive my 2016 GMC Sierra if the OBDII code B374A related to the Air Flow Control Position Feedback Circuit keeps coming back after repairs?

- If the code keeps reappearing after repairs, there may be an ongoing issue that needs further inspection. Continuing to drive the vehicle without addressing the root cause can lead to more serious problems.

8. Are there any preventative maintenance measures I can take to avoid OBDII code B374A in my 2016 GMC Sierra?

- Regularly inspecting and maintaining the air flow sensor, checking the wiring and connectors for any signs of wear or damage, and following the manufacturer's recommended maintenance schedule can help prevent this code from appearing.