AutoCodes – Generic – B3764

B3764 Code - Auxiliary HVAC Door Actuator Range/Performance

Quick Answer

The Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) Control Module controls the auxiliary HVAC door actuators to regulate the airflow through the auxiliary HVAC system. 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: B3764 indicates Auxiliary HVAC Door Actuator Range/Performance.
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 1,955

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 B3764 Description

The Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) Control Module controls the auxiliary HVAC door actuators to regulate the airflow through the auxiliary HVAC system. Each actuator consists of a stepper motor, a logic circuit, and a potentiometer. The potentiometer inside the door actuator allows the module to monitor the current position of the actuator drive shaft. The module supplies a 5-volt source voltage to the potentiometer on the 5-volt reference circuit. The module supplies ground to the potentiometer through the low reference circuit. The auxiliary 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 module converts the voltage value to a count value where 1 volt is approximately equal to 51 counts.
The auxiliary HVAC control module calibrates the travel range of the auxiliary HVAC door actuators when it is initially powered by the battery positive voltage circuit. During calibration, the module commands the actuators in each direction until door travel is stopped. The module stores the minimum door positions and the maximum door positions of each actuator into memory. The total travel range is calculated by subtracting the minimum door position from the maximum door position. The door actuators can be calibrated again with a scan tool.

OBDII Code B3764 - Auxiliary HVAC Door Actuator Range/Performance - AutoCodes.com — B3764 Code - Auxiliary HVAC Door Actuator Range/Performance

What does this mean?

What are the Possible Causes of the DTC B3764?

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

How to Fix the DTC B3764?

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 B3764 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 B3764 code?

Need more information on how to fix the B3764 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B3764 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B3764 Buick — Auxiliary HVAC Door Actuator Range/Performance
B3764 Cadillac — Auxiliary HVAC Door Actuator Range/Performance
B3764 Chevrolet — Auxiliary HVAC Door Actuator Range/Performance
B3764 GMC — Auxiliary HVAC Door Actuator Range/Performance

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 B3764 Code

1. What are common symptoms of OBDII code B3764 (Auxiliary HVAC Door Actuator Range/Performance)?

- Common symptoms include inconsistent airflow from the HVAC system, difficulty adjusting temperature settings, and unusual clicking noises coming from the dashboard.

2. What causes OBDII code B3764 to trigger?

- The code B3764 is typically triggered when the auxiliary HVAC door actuator, responsible for controlling airflow in the HVAC system, malfunctions or fails to operate within the expected range.

3. How can I diagnose the issue related to OBDII code B3764?

- To diagnose the issue, you can use a diagnostic scan tool to retrieve the specific code, inspect the auxiliary HVAC door actuator for any visible damage, and perform a system check to ensure all components are functioning properly.

4. Can a faulty blend door actuator cause OBDII code B3764 to be set?

- Yes, a faulty blend door actuator, which controls the temperature blend in the HVAC system, can contribute to triggering OBDII code B3764 if it affects the overall performance of the auxiliary HVAC door actuator.

5. What are some repair tips for addressing OBDII code B3764?

- Repair tips include replacing the faulty auxiliary HVAC door actuator, checking and potentially replacing related components such as blend door actuators, and ensuring proper calibration of the HVAC system after repairs.

6. Is it safe to continue driving with OBDII code B3764 present?

- While it may be safe to drive with this code present, it is recommended to address the issue promptly to avoid potential HVAC system malfunctions and discomfort while driving.

7. Can resetting the OBDII system clear code B3764?

- Resetting the OBDII system may temporarily clear the code, but it is important to diagnose and address the underlying issue causing code B3764 to prevent it from reoccurring.

8. Are there any common mistakes to avoid when dealing with OBDII code B3764?

- Common mistakes to avoid include ignoring the symptoms, replacing parts without proper diagnosis, and neglecting regular maintenance of the HVAC system, which can lead to recurring issues.

9. How much does it typically cost to repair OBDII code B3764?

- The cost of repairing OBDII code B3764 can vary depending on the extent of the issue, the need for parts replacement, and labor costs. It is recommended to consult a professional for an accurate estimate.

10. Can a DIY enthusiast fix OBDII code B3764 at home?

- While some DIY enthusiasts may have the skills to address OBDII code B3764 at home, it is important to have the necessary tools, knowledge, and experience to properly diagnose and repair the issue to avoid causing further damage.