AutoCodes – Chevrolet – B3779 Chevrolet

B3779 Chevrolet Code - Air Flow Control 9

Quick Answer

The Heating, Ventilation, and Air Conditioning (HVAC) control module controls the HVAC door actuators to regulate the airflow through the HVAC system. 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: B3779 Chevrolet indicates Air Flow Control 9.
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 31,547

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 16, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B3779 Chevrolet Description

The Heating, Ventilation, and Air Conditioning (HVAC) control module controls the HVAC door actuators to regulate the airflow through the HVAC system. Each actuator consists of an electric motor and a potentiometer. The module supplies a low reference and 5-volt reference source voltage to the potentiometer. The HVAC control module monitors the voltage drop across the potentiometer on the door position signal circuit. When the actuator shaft rotates, the voltage on the door position signal circuit changes. The control circuit uses either a 0, 2.5 or 5-volt signal to command the actuator movement. When the actuator is at rest, the control circuit value is 2.5 volts. A 0 or 5-volt control signal commands the actuator movement in opposite directions.

OBDII Code B3779 Chevrolet - Air Flow Control 9 - AutoCodes.com — B3779 Chevrolet Code - Air Flow Control 9

What does this mean?

What are the Possible Causes of the DTC B3779 Chevrolet?

Faulty Mode Actuator
Mode Actuator harness is open or shorted
Mode Actuator circuit poor electrical connection
Faulty Heating and Cooling Systems (HVAC) Control Module

How to Fix the DTC B3779 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 does this mean?

Code Tech Notes

B3779 02 Air Flow Control 9 Feedback Circuit Short to Ground
B3779 05 Air Flow Control 9 Feedback Circuit Short to Battery or Open
B3779 61 Air Flow Control 9 Circuit Actuator Stuck

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B3779 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 B3779 Chevrolet code?

Need more information on how to fix the B3779 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3779 Chevrolet 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 B3779 Chevrolet Code

1. What are the common symptoms of OBDII code B3779 in a Chevrolet related to Air Flow Control 9?

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

2. What could cause the OBDII code B3779 to trigger in a Chevrolet indicating Air Flow Control 9 issues?

- The code may be triggered due to a faulty air flow sensor, a vacuum leak, or a problem with the air intake system.

3. How can I diagnose the OBDII code B3779 in my Chevrolet for Air Flow Control 9 problems?

- Diagnosis involves checking the air flow sensor, inspecting the air intake system for leaks, and testing the vacuum lines for any issues.

4. What are the potential consequences of ignoring the OBDII code B3779 related to Air Flow Control 9 in a Chevrolet?

- Ignoring the code may lead to reduced engine performance, increased emissions, and potential damage to other engine components.

5. Can a DIY enthusiast repair the OBDII code B3779 in a Chevrolet caused by Air Flow Control 9 issues?

- Depending on the exact cause, some DIY repairs may be possible such as cleaning or replacing the air flow sensor, fixing vacuum leaks, or replacing damaged intake components.

6. Is it safe to continue driving my Chevrolet with the OBDII code B3779 indicating Air Flow Control 9 problems?

- It is not recommended to drive the vehicle for an extended period with this code active, as it may lead to further engine damage and decreased performance.

7. How much can I expect to pay for professional repairs related to the OBDII code B3779 in a Chevrolet due to Air Flow Control 9 issues?

- Repair costs can vary depending on the exact cause, but expect to pay anywhere from $100 to $500 for parts and labor.

8. Are there any preventive maintenance tips to avoid the OBDII code B3779 related to Air Flow Control 9 in a Chevrolet?

- Regularly inspecting and maintaining the air intake system, replacing air filters as recommended, and ensuring proper engine maintenance can help prevent this code from appearing.

9. Is resetting the OBDII code B3779 related to Air Flow Control 9 in a Chevrolet a temporary fix?

- Resetting the code without addressing the underlying issue is only a temporary solution and will likely cause the code to reappear once the problem persists.

10. How long does it typically take to repair the OBDII code B3779 in a Chevrolet caused by Air Flow Control 9 issues?

- Repair times can vary depending on the exact cause, but most repairs related to this code can be completed within a few hours to a day by a professional mechanic.