AutoCodes – Saturn – B3779 Saturn

B3779 Saturn 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 Saturn 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 1,084

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 Saturn 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 Saturn - Air Flow Control 9 - AutoCodes.com — B3779 Saturn Code - Air Flow Control 9

What does this mean?

What are the Possible Causes of the DTC B3779 Saturn?

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 Saturn?

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 Saturn 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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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 Saturn Code

1. What does the OBDII code B3779 mean on a Saturn?

The B3779 code refers to an issue with the "Air Flow Control 9" circuit, indicating a malfunction in the HVAC system's ability to control airflow as directed by the climate control module.

2. What are the common symptoms of the B3779 code on a Saturn?

Symptoms may include improper or inconsistent airflow from the vents, inability to control the direction of air (e.g., defrost, floor, or dash vents), and potential climate control error messages.

3. What causes the B3779 code to appear?

Common causes include a faulty airflow control actuator, wiring issues like damaged or corroded connectors, or a malfunctioning HVAC control module.

4. How can I diagnose the B3779 code on my Saturn?

Start by checking the airflow control actuator and associated wiring for damage or corrosion. Use a scan tool to confirm the code and test the actuator's operation through the HVAC control module.

5. Can I drive my Saturn with the B3779 code active?

Yes, you can typically drive with this code, but you may experience discomfort due to limited or incorrect airflow from the HVAC system.

6. How do I fix the B3779 code on a Saturn?

Repairs may include replacing the faulty airflow control actuator, repairing damaged wiring or connectors, or reprogramming or replacing the HVAC control module if necessary.

7. How much does it cost to fix the B3779 code on a Saturn?

The cost depends on the exact cause, but replacing an airflow control actuator typically ranges from $150 to $400, including parts and labor.

8. Can a blown fuse cause the B3779 code?

Yes, a blown HVAC system fuse could disrupt the power supply to the airflow control actuator, triggering the B3779 code.

9. Is the B3779 code specific to Saturn vehicles?

While the code may appear on other GM vehicles, it is most commonly associated with Saturn models that use GM's HVAC control systems.

10. Do I need special tools to fix the B3779 code?

A scan tool with HVAC diagnostics capability is recommended for proper diagnosis. Basic tools like screwdrivers and multimeters may also be needed to inspect and repair the actuator or wiring.