AutoCodes – GMC – B3782 GMC

B3782 GMC Code - Air Flow Control 10 Feedback Circuit Malfunction

Quick Answer

The actuators operate using 5 circuits. Common causes include Faulty Auxiliary Mode Actuator, Auxiliary Mode Actuator harness is open or shorted, Auxiliary 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: B3782 GMC indicates Air Flow Control 10 Feedback Circuit Malfunction.
Common causes: Common causes include Faulty Auxiliary Mode Actuator, Auxiliary Mode Actuator harness is open or shorted, Auxiliary 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 10,861

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 15, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3782 GMC Description

The actuators operate using 5 circuits. A 5-volt reference, low reference, signal circuit and two bi-directional 0 or 12 volt control circuits. The Heating, Ventilation, and Air Conditioning (HVAC) Control Module supplies a low reference and 5-volt reference to the potentiometer. The HVAC control module monitors the voltage drop across the potentiometer on the door position signal circuit. As the actuator door changes position the door position signal circuit voltage also changes. The two bi-directional control circuits enable the actuator to operate. Both circuits are set to 0 volts when the HVAC control module detects, from the feedback potentiometer, that the actuator is in the desired position. In order to move the actuator, the HVAC control module switches the appropriate control circuit to 12 volts.

OBDII Code B3782 GMC - Air Flow Control 10 Feedback Circuit Malfunction - AutoCodes.com — B3782 GMC Code - Air Flow Control 10 Feedback Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC B3782 GMC?

Faulty Auxiliary Mode Actuator
Auxiliary Mode Actuator harness is open or shorted
Auxiliary Mode Actuator circuit poor electrical connection
Faulty Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) Control Module

How to Fix the DTC B3782 GMC?

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 B3782 GMC 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 B3782 GMC 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 B3782 GMC Code

1. What does the OBDII code B3782 mean on a GMC vehicle?

B3782 indicates a malfunction in the Air Flow Control 10 Feedback Circuit, which is responsible for monitoring or controlling airflow in the HVAC system.

2. What are the common symptoms of code B3782 in a GMC?

Symptoms may include improper HVAC airflow direction, inability to change vent modes, unusual noises from the vents, or the HVAC system not responding to input.

3. What causes the B3782 code to appear in a GMC?

Common causes include a faulty air flow control actuator, wiring issues such as damaged or loose connections, a malfunctioning control module, or physical obstructions in the HVAC system.

4. Can I still drive my GMC with the B3782 code active?

Yes, the vehicle is drivable, but the HVAC system may not function properly, leading to discomfort or reduced defrosting ability in certain weather conditions.

5. How do I diagnose the B3782 code on my GMC?

Start by inspecting the air flow actuator and its wiring for damage or loose connections, then use a scan tool to monitor the circuit signal and test the actuator's operation.

6. How can I fix the B3782 code in my GMC?

Repairs may involve replacing a defective air flow control actuator, repairing or replacing damaged wiring, or reprogramming or replacing the HVAC control module if necessary.

7. How much does it cost to repair the B3782 code on a GMC?

The cost depends on the specific issue but typically ranges from $100 to $400, with actuator replacement being the most common repair.

8. Can I clear the B3782 code without fixing the problem?

You can clear the code with an OBDII scanner, but if the underlying issue is not resolved, the code will likely return.

9. What tools are needed to troubleshoot the B3782 code on a GMC?

You may need an OBDII scanner, a multimeter for testing electrical circuits, and basic hand tools to access the HVAC components.

10. Is the B3782 code related to other HVAC issues in a GMC?

Yes, this code can sometimes be accompanied by other HVAC-related codes if there are broader issues with the system, such as multiple actuator or control module failures.