AutoCodes – GMC – B0423 GMC

B0423 GMC Code - Right Temperature Control Feedback Circuit

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 Passenger Air Temperature Actuator, Passenger Air Temperature Actuator harness is open or shorted, Passenger Air Temperature Actuator circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: B0423 GMC indicates Right Temperature Control Feedback Circuit.
Common causes: Common causes include Faulty Passenger Air Temperature Actuator, Passenger Air Temperature Actuator harness is open or shorted, Passenger Air Temperature Actuator circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 20,132

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 29, 2024

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B0423 GMC 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 B0423 GMC - Right Temperature Control Feedback Circuit - AutoCodes.com — B0423 GMC Code - Right Temperature Control Feedback Circuit

What does this mean?

What are the Possible Causes of the DTC B0423 GMC?

Faulty Passenger Air Temperature Actuator
Passenger Air Temperature Actuator harness is open or shorted
Passenger Air Temperature Actuator circuit poor electrical connection

How to Fix the DTC B0423 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 does this mean?

Code Tech Notes

B0423:02 Temperature Control 2 Feedback Circuit Short to Ground
B0423:05 Temperature Control 2 Feedback Circuit Short to Battery or Open
B0423:61 Temperature Control 2 Circuit Actuator Stuck

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B0423 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 B0423 GMC code?

Need more information on how to fix the B0423 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B0423 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

B0423 2014 GMC Sierra — Right Temperature Control Feedback Circuit
B0423 2015 GMC Sierra — Right Temperature Control Feedback Circuit
B0423 2016 GMC Sierra — Right Temperature Control Feedback Circuit
B0423 2017 GMC Sierra — Right Temperature Control Feedback Circuit
B0423 2018 GMC Sierra — Right Temperature Control Feedback Circuit

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 B0423 GMC Code

1. What are the common symptoms of OBDII code B0423 GMC?

- Common symptoms include inconsistent temperature control on the right side of the vehicle, warm air blowing when set to cool, or cool air blowing when set to warm.

2. What does the OBDII code B0423 GMC indicate?

- This code indicates a problem with the right temperature control feedback circuit in the GMC vehicle.

3. What are the possible causes of OBDII code B0423 GMC?

- Possible causes include a faulty temperature control actuator, damaged wiring or connectors in the feedback circuit, or a problem with the HVAC control module.

4. How can I diagnose the issue related to OBDII code B0423 GMC?

- Diagnose the issue by using a scan tool to retrieve the code, checking the temperature control actuators, inspecting wiring and connectors for damage, and testing the HVAC control module.

5. How can I repair OBDII code B0423 GMC?

- Repair options may include replacing the faulty temperature control actuator, repairing damaged wiring or connectors, or resetting the HVAC control module.

6. Can I drive my GMC with OBDII code B0423 without immediate repair?

- It is generally safe to drive the vehicle with this code, but it is recommended to address the issue promptly to avoid discomfort and potential further damage.

7. Is OBDII code B0423 GMC a serious problem?

- While it may not affect the overall drivability of the vehicle, ignoring this code can lead to discomfort due to improper temperature control and may impact the HVAC system's performance.

8. How much does it cost to fix OBDII code B0423 GMC?

- The cost of fixing this code can vary depending on the exact cause of the issue, but it may involve replacement parts and labor costs.

9. Can I reset OBDII code B0423 GMC without repairs?

- Resetting the code without addressing the underlying issue may temporarily clear the warning light, but it is not recommended as the problem will likely reoccur.

10. How can I prevent OBDII code B0423 GMC from happening again?

- To prevent this code from occurring again, perform regular maintenance on the HVAC system, address any temperature control issues promptly, and ensure proper functioning of all related components.