AutoCodes – Cadillac – B3779 Cadillac

B3779 Cadillac 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 Cadillac 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 3,795

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

What does this mean?

What are the Possible Causes of the DTC B3779 Cadillac?

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 Cadillac?

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 Cadillac 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 Cadillac Code

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

The common symptoms include poor engine performance, rough idling, and potential stalling of the vehicle.

2. What are some possible causes of OBDII code B3779 in a Cadillac associated with Air Flow Control 9?

Possible causes may include a faulty air flow control sensor, issues with the air flow control actuator, or a wiring/connection problem.

3. How can I diagnose the OBDII code B3779 in a Cadillac for Air Flow Control 9 issues?

Diagnosis typically involves using a scan tool to retrieve the specific code, checking the air flow control sensor readings, and inspecting the related components for any visible damage or malfunctions.

4. Can a dirty air filter trigger OBDII code B3779 in a Cadillac related to Air Flow Control 9?

Yes, a dirty or clogged air filter can disrupt the air flow in the system, potentially leading to issues that trigger this OBDII code.

5. What are some repair tips for resolving OBDII code B3779 in a Cadillac tied to Air Flow Control 9 problems?

Repair tips may include cleaning or replacing the air flow control sensor, inspecting and repairing any damaged wiring, and ensuring proper connection of the air flow control components.

6. Is it safe to continue driving a Cadillac with OBDII code B3779 related to Air Flow Control 9?

It is not recommended to continue driving the vehicle with this code present, as it can lead to further engine problems and potentially cause safety issues.

7. Can resetting the OBDII system clear the B3779 code in a Cadillac linked to Air Flow Control 9?

Resetting the system may temporarily clear the code, but if the underlying issue causing the code is not addressed, it is likely to reappear.

8. How much does it typically cost to repair OBDII code B3779 in a Cadillac associated with Air Flow Control 9?

The cost of repair can vary depending on the specific issue causing the code, but it may range from a few hundred to over a thousand dollars, including parts and labor.

9. Are there any preventive measures to avoid OBDII code B3779 in a Cadillac related to Air Flow Control 9?

Regular maintenance, such as changing air filters and monitoring engine performance, can help prevent issues that may trigger this OBDII code.

10. Can a DIY enthusiast without specialized tools fix OBDII code B3779 in a Cadillac for Air Flow Control 9 problems?

While some basic troubleshooting steps can be performed by a DIY enthusiast, diagnosing and repairing complex issues related to this code may require professional expertise and specialized tools.