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C0379ModerateChassis

C0379 on 2007-2022 GMC Sierra 3500HD — Transfer Case / Front Axle Actuator Circuit (manufacturer-specific)

1 vehicles · 1 makes · $150-$800 repair

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Most Reported On

2007-2022GMC Sierra 3500HD

C0379 is an OBD-II diagnostic trouble code meaning “Transfer Case / Front Axle Actuator Circuit (manufacturer-specific).” C0379 is a manufacturer-specific chassis code generally associated with the transfer case and front axle actuator system on four-wheel-drive vehicles. It typically indicates the control module detected a fault related to engaging/disengaging the front axle (such as the front axle disconnect actuator) or its circuit. Because the exact definition varies by manufacturer and model, the precise meaning should be verified with OEM service data. The likely effect is impaired or unavailable 4WD engagement rather than a braking issue. This code is most commonly reported on 2007-2022 GMC Sierra 3500HD, with repair costs ranging from $150 to $800.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (1)
  • Related Codes
  • FAQ
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Common Causes

1Faulty front axle disconnect actuator
2Damaged actuator wiring or connector
3Transfer case encoder/actuator fault
4Corroded or poor ground connection
5Failing transfer case control module
6Mechanical binding in the front axle engagement
7Low system voltage

Typical Repair Cost

$150 - $800

Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.

Diagnostic Tools

To diagnose C0379, you'll need an OBD-II scanner. Here are our recommendations at every price point.

Budget Pick$10–$20

ANCEL AD310 Classic OBD-II Scanner

by ANCEL

A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).

  • Read & clear engine codes
  • View freeze frame data
  • I/M readiness status
  • No batteries or app needed
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Best Value$90–$120

BlueDriver Pro Bluetooth Scanner

by BlueDriver

Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.

  • Enhanced diagnostics (ABS, SRS, transmission)
  • Repair Reports with verified fixes
  • Smog check readiness
  • Free app (iOS & Android)
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Advanced$180–$230

LAUNCH CRP123X OBD-II Scanner

by LAUNCH

A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.

  • Engine, transmission, ABS, SRS diagnostics
  • Live data stream & graphing
  • AutoVIN for vehicle identification
  • Free lifetime updates via Wi-Fi
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Professional$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

by Autel

Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.

  • All-system diagnostics (25+ modules)
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  • Oil reset, EPB, BMS, TPMS, injector coding
  • 7-inch touchscreen with Android OS
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Vehicles Affected (1)

GMC C0379 page →
Sierra 3500HDModerate

Front Differential Actuator Failure Causing 4WD Engagement Problems

2007-2022$150-$800220 reports

Related Codes (8)

C0374Transfer Case / Automatic 4WD System Malfunction (manufacturer-specific)C0031Left Front Wheel Speed Sensor CircuitC0034Right Front Wheel Speed Sensor CircuitC0036Left Front Wheel Speed Sensor CircuitC0037Left Rear Wheel Speed Sensor CircuitC0038Left Rear Wheel Speed Sensor CircuitC003ARight Rear Wheel Speed Sensor CircuitC003BRight Rear Wheel Speed Sensor Supply Circuit

FAQ

What does C0379 mean?

C0379 stands for "Transfer Case / Front Axle Actuator Circuit (manufacturer-specific)." C0379 is a manufacturer-specific chassis code generally associated with the transfer case and front axle actuator system on four-wheel-drive vehicles. It typically indicates the control module detected a fault related to engaging/disengaging the front axle (such as the front axle disconnect actuator) or its circuit. Because the exact definition varies by manufacturer and model, the precise meaning should be verified with OEM service data. The likely effect is impaired or unavailable 4WD engagement rather than a braking issue.

What are the most common causes of C0379?

The most common causes of C0379 are: Faulty front axle disconnect actuator, Damaged actuator wiring or connector, Transfer case encoder/actuator fault, Corroded or poor ground connection, Failing transfer case control module, Mechanical binding in the front axle engagement, Low system voltage. The specific cause varies by vehicle.

How much does it cost to fix C0379?

Repair costs for C0379 range from $150 to $800, depending on the vehicle and root cause.

Which vehicles are affected by C0379?

Au7o has documented C0379 across 1 vehicle models from 1 manufacturers: GMC.

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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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