AutoCodes – GMC – C0379 2016 GMC Sierra

C0379 2016 GMC Sierra Code - Front Axle Switch Circuit

Quick Answer

The front axle control circuit consists of an electric motor actuator that engages and disengages the front axle. Common causes include Faulty Front Axle Engagement Actuator, Front Axle Engagement Actuator harness is open or shorted, Front Axle Engagement 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: C0379 2016 GMC Sierra indicates Front Axle Switch Circuit.
Common causes: Common causes include Faulty Front Axle Engagement Actuator, Front Axle Engagement Actuator harness is open or shorted, Front Axle Engagement 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 260

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 Jul 11, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C0379 2016 GMC Sierra Description

The front axle control circuit consists of an electric motor actuator that engages and disengages the front axle. The front axle engagement actuator consists of a permanent magnetic motor, a worm gear-controlled plunger, a front axle switch, and an electronic control circuit within the actuator assembly.
The front axle engagement actuator contains the following circuits: A Run/Crank Ignition 1 Voltage circuit, a Four-Wheel Drive Wheel Lock Indicator circuit, a Front Axle Actuator Control circuit, and a ground circuit.
When a shift to 4WD Auto, 4WD High, or 4WD Low is requested, the Transfer Case Control Module engages the front axle by grounding the front axle actuator control circuit through a current limiting driver.
This Diagnostic Trouble Code (DTC) will be set when a short to ground, short to voltage, or open circuit is detected.

OBDII Code C0379 2016 GMC Sierra - Front Axle Switch Circuit - AutoCodes.com — C0379 2016 GMC Sierra Code - Front Axle Switch Circuit

What does this mean?

What are the Possible Causes of the DTC C0379 2016 GMC Sierra?

Faulty Front Axle Engagement Actuator
Front Axle Engagement Actuator harness is open or shorted
Front Axle Engagement Actuator circuit poor electrical connection
Faulty Transfer Case Control Module

How to Fix the DTC C0379 2016 GMC Sierra?

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 C0379 2016 GMC Sierra 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 C0379 2016 GMC Sierra 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 C0379 2016 GMC Sierra Code

What does the OBDII code C0379 mean for a 2016 GMC Sierra?

C0379 indicates a problem with the front axle switch circuit, which is responsible for controlling the operation of the front axle in four-wheel drive systems.

What are common symptoms of the C0379 code?

Common symptoms include the inability to engage four-wheel drive, warning lights on the dashboard, and unusual noises from the front axle area.

What might cause the C0379 code to trigger?

Causes can include a faulty front axle switch, damaged wiring or connectors, a malfunctioning control module, or issues with the front axle itself.

How can I diagnose the C0379 code?

Start by using an OBDII scanner to confirm the code. Inspect the front axle switch, wiring, and connectors for damage. Check for any related codes that could provide additional context.

What repairs are typically needed for a C0379 code?

Repairs may involve replacing the front axle switch, repairing damaged wiring, or addressing issues with the control module or front axle assembly.

Can I drive my GMC Sierra with the C0379 code?

It's not recommended to drive the vehicle if the front axle isn't functioning correctly, as it can affect handling and safety, especially in adverse conditions.

How can I prevent the C0379 code from occurring?

Regular maintenance, including checking the condition of the front axle system and ensuring connections are tight and free of corrosion, can help prevent issues.

Is it safe to clear the C0379 code without repairs?

Clearing the code may temporarily turn off the warning light, but it does not fix the underlying issue and could lead to further damage or unsafe driving conditions.

What should I do if the C0379 code returns after repairs?

If the code reappears, further diagnostics may be necessary. It's advisable to check for additional related codes and inspect the system again for any overlooked issues.

Can the C0379 code affect fuel efficiency?

While the C0379 code itself may not directly impact fuel efficiency, driving in four-wheel drive when not needed can lead to increased fuel consumption.