AutoCodes – Chevrolet – B374A 2018 Chevrolet Silverado

B374A 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado 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 1,137

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 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado - Air Flow Control Position Feedback Circuit - AutoCodes.com — B374A 2018 Chevrolet Silverado Code - Air Flow Control Position Feedback Circuit

What does this mean?

What are the Possible Causes of the DTC B374A 2018 Chevrolet Silverado?

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 2018 Chevrolet Silverado?

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 2018 Chevrolet Silverado 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 2018 Chevrolet Silverado code?

Need more information on how to fix the B374A 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B374A 2018 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

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 2018 Chevrolet Silverado Code

1. What are common symptoms of OBDII code B374A in a 2018 Chevrolet Silverado?

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

2. What causes the OBDII code B374A in a 2018 Chevrolet Silverado?

- The B374A code typically indicates a fault in the air flow control position feedback circuit, which could be caused by a faulty sensor, wiring issue, or a problem with the control module.

3. How can I diagnose the issue related to OBDII code B374A in my 2018 Chevrolet Silverado?

- To diagnose the issue, you can use an OBDII scanner to read the trouble codes and then perform a visual inspection of the wiring and sensor connections. Testing the sensor and related components may also be necessary.

4. Is it safe to continue driving with OBDII code B374A in my 2018 Chevrolet Silverado?

- It is not recommended to continue driving with the B374A code present, as it can lead to further damage to the engine or components. It's best to address the issue promptly.

5. How can I repair the air flow control position feedback circuit issue causing OBDII code B374A in my 2018 Chevrolet Silverado?

- Repairing the issue may involve replacing the faulty sensor, repairing any damaged wiring, or reprogramming the control module. It's recommended to consult a professional mechanic for proper diagnosis and repair.

6. Can a DIY enthusiast fix the OBDII code B374A in a 2018 Chevrolet Silverado?

- While some DIY enthusiasts may be able to address simple wiring issues or replace sensors, diagnosing and repairing the root cause of the B374A code may require specialized tools and expertise, so professional assistance is often recommended.

7. What is the typical cost to repair OBDII code B374A in a 2018 Chevrolet Silverado?

- The cost of repairing the B374A code can vary depending on the specific cause of the issue and the labor rates in your area. It's advisable to get estimates from multiple mechanics before proceeding with repairs.

8. Will resetting the OBDII code B374A in my 2018 Chevrolet Silverado make it go away permanently?

- Simply resetting the code may temporarily clear the check engine light, but if the underlying issue causing the B374A code is not addressed, the code is likely to return. It's important to diagnose and repair the root cause of the problem.

9. How long does it typically take to repair OBDII code B374A in a 2018 Chevrolet Silverado?

- The repair time for the B374A code can vary depending on the exact cause of the issue and the complexity of the repair. It may take anywhere from a few hours to a full day to diagnose and fix the problem.

10. Can extreme weather conditions affect the occurrence of OBDII code B374A in a 2018 Chevrolet Silverado?

- Extreme weather conditions, such as extreme heat or cold, can potentially affect the performance of sensors and components related to the air flow control system, which could contribute to the occurrence of the B374A code.