AutoCodes – GMC – B0145 GMC

B0145 GMC Code - Auxiliary Mode Actuator

Quick Answer

The Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) actuators are a 5-wire bi-directional electric motor that incorporates a feedback potentiometer. Common causes include Faulty Auxiliary Mode Actuator, Auxiliary Mode Actuator harness is open or shorted, Auxiliary Mode 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: B0145 GMC indicates Auxiliary Mode Actuator.
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: 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 2,325

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 10, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B0145 GMC Description

The Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) actuators are a 5-wire bi-directional electric motor that incorporates a feedback potentiometer. Low reference, 5-volt reference, position signal, and 2 control circuits enable the actuator to operate. The control circuits use either a 0 or 12 volt value to coordinate the actuator movement. When the actuator is at rest, both control circuits have a value of 0 volts. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 volts. The auxiliary HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction. When the actuator shaft rotates, the potentiometers adjustable contact changes the door position signal between 0-5 volts. This signal then is converted into a count value where as 1 volt will equal 51 counts.
The auxiliary HVAC control module calibrates the travel range of the 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.

OBDII Code B0145 GMC - Auxiliary Mode Actuator - AutoCodes.com — B0145 GMC Code - Auxiliary Mode Actuator

What does this mean?

What are the Possible Causes of the DTC B0145 GMC?

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

How to Fix the DTC B0145 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 B0145 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.

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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 B0145 GMC Code

1. What are common symptoms of OBDII code B0145 in a GMC related to the Auxiliary Mode Actuator?

The common symptoms of OBDII code B0145 in a GMC include inconsistent air distribution from the HVAC system, inability to switch between different air flow modes, or unusual noises coming from the air vents.

2. What can cause OBDII code B0145 in a GMC to trigger?

The OBDII code B0145 in a GMC is typically triggered when there is a malfunction in the Auxiliary Mode Actuator, which controls the direction of air flow in the HVAC system.

3. How can I diagnose the issue causing OBDII code B0145 in my GMC?

Diagnosing the issue causing OBDII code B0145 in your GMC involves checking the Auxiliary Mode Actuator for proper operation, inspecting the wiring and connectors for damage, and using a scan tool to retrieve specific error codes.

4. Is it safe to continue driving with OBDII code B0145 in my GMC?

While it may be safe to drive with OBDII code B0145 in your GMC, it is recommended to address the issue promptly to avoid potential discomfort due to improper air flow and prevent further damage to the HVAC system.

5. Can I repair OBDII code B0145 in my GMC myself?

Repairing OBDII code B0145 in your GMC may require mechanical expertise and specialized tools. It is recommended to consult a professional mechanic to accurately diagnose and repair the issue with the Auxiliary Mode Actuator.

6. How much does it typically cost to repair OBDII code B0145 in a GMC?

The cost to repair OBDII code B0145 in a GMC can vary depending on the extent of the damage, parts needed for replacement, and labor costs. It is advisable to obtain quotes from different auto repair shops for an accurate estimate.

7. Are there any preventive measures to avoid OBDII code B0145 in a GMC?

To prevent OBDII code B0145 in a GMC, it is essential to perform regular maintenance on the HVAC system, address any air flow issues promptly, and avoid overloading the Auxiliary Mode Actuator with excessive demands.

8. Can extreme weather conditions contribute to triggering OBDII code B0145 in a GMC?

Extreme weather conditions, such as extreme heat or cold, can potentially strain the Auxiliary Mode Actuator in a GMC, leading to malfunctions that may trigger OBDII code B0145. Proper maintenance and care during such conditions can help prevent issues.

9. Are there any recalls or technical service bulletins related to OBDII code B0145 in GMC vehicles?

It is advisable to check with the manufacturer or authorized dealerships for any recalls or technical service bulletins related to OBDII code B0145 in GMC vehicles, as they may provide information on common issues and solutions.

10. How long does it typically take to repair OBDII code B0145 in a GMC?

The time required to repair OBDII code B0145 in a GMC can vary depending on the complexity of the issue, availability of parts, and the mechanic's expertise. It is recommended to consult with the repair shop for a more accurate timeline.