AutoCodes – GMC – C0397 GMC

C0397 GMC Code - Transfer Case Clutch

Quick Answer

In 4WD/AWD Automatic range, the Transfer Case Control Module monitors the front and rear wheel speed sensors for slip. Common causes include Faulty Transfer Case Motor (Transfer Case Two/Four Wheel Drive Actuator), Transfer Case Motor harness is open or shorted, Transfer Case Motor 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: C0397 GMC indicates Transfer Case Clutch.
Common causes: Common causes include Faulty Transfer Case Motor (Transfer Case Two/Four Wheel Drive Actuator), Transfer Case Motor harness is open or shorted, Transfer Case Motor 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 6,307

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
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code C0397 GMC Description

In 4WD/AWD Automatic range, the Transfer Case Control Module monitors the front and rear wheel speed sensors for slip. If the Transfer Case Control Module detects slip and is unable to correct for a difference between the front and rear speed sensors, it will command the transfer case to apply the clutch. In addition, the Transfer Case Control Module tests for clutch pack wear by performing a high side kiss point check at power down and comparing it to the transfer case range actuator position sensor reading.

OBDII Code C0397 GMC - Transfer Case Clutch - AutoCodes.com — C0397 GMC Code - Transfer Case Clutch

What does this mean?

What are the Possible Causes of the DTC C0397 GMC?

Faulty Transfer Case Motor (Transfer Case Two/Four Wheel Drive Actuator)
Transfer Case Motor harness is open or shorted
Transfer Case Motor circuit poor electrical connection
Faulty Transfer Case Control Module

How to Fix the DTC C0397 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

C0397:54 Transfer Case Clutch High Temperature
C0397:58 Transfer Case Clutch Performance
C0397:4B (if equipped) Transfer Case Clutch Calibration Not Learned
C0397:F3 Transfer Case Clutch Worn Out Clutch
C0397:F4 Transfer Case Range Position Sensor Over Travel

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C0397 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 C0397 GMC code?

Need more information on how to fix the C0397 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C0397 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

C0397 2014 GMC Sierra — Transfer Case Clutch
C0397 2015 GMC Sierra — Transfer Case Clutch
C0397 2016 GMC Sierra — Transfer Case Clutch
C0397 2017 GMC Sierra — Transfer Case Clutch
C0397 2018 GMC Sierra — Transfer Case Clutch

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 C0397 GMC Code

1. What does the OBDII code C0397 mean on a GMC?

C0397 indicates an issue with the transfer case clutch control circuit, often related to the system that engages or disengages the transfer case in 4WD vehicles.

2. What are the common symptoms of code C0397 in a GMC?

Symptoms may include the "Service 4WD" message on the dashboard, trouble shifting into or out of 4WD modes, unusual noises from the transfer case, or reduced 4WD functionality.

3. What causes the C0397 code to appear on a GMC vehicle?

Common causes include a faulty transfer case clutch solenoid, damaged wiring or connectors in the circuit, low or contaminated transfer case fluid, or a malfunctioning transfer case control module.

4. How can I fix the C0397 code on my GMC?

Inspect and repair any damaged wiring or connectors, replace the transfer case clutch solenoid if it's faulty, ensure the transfer case fluid is clean and at the correct level, or reprogram/replace the transfer case control module if necessary.

5. Can driving with the C0397 code damage my GMC?

Driving with this code may not immediately cause damage, but ignoring it can lead to further wear on the transfer case or drivetrain components, especially if the 4WD system is malfunctioning.

6. How can I diagnose the C0397 code on my GMC?

Use an OBDII scanner to confirm the code, visually inspect the wiring and connectors for damage, test the transfer case clutch solenoid for proper operation, and check the fluid condition in the transfer case.

7. Is the C0397 code unique to GMC vehicles?

While C0397 is a generic OBDII code, it is commonly associated with GMC and other General Motors vehicles equipped with transfer cases.

8. Will resetting the code fix the C0397 issue on my GMC?

Resetting the code may temporarily clear it, but the underlying issue must be resolved to prevent the code from returning.

9. How much does it cost to fix the C0397 code on a GMC?

Repair costs vary but may range from $100 to $500, depending on whether you need to replace the solenoid, wiring, or transfer case control module.

10. Can low transfer case fluid cause the C0397 code in a GMC?

Yes, low or contaminated transfer case fluid can cause the transfer case clutch to malfunction, triggering the C0397 code. Always ensure the fluid is at the proper level and in good condition.