AutoCodes – GMC – C0397 2018 GMC Sierra

C0397 2018 GMC Sierra 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 2018 GMC Sierra 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 298

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 2018 GMC Sierra 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 2018 GMC Sierra - Transfer Case Clutch - AutoCodes.com — C0397 2018 GMC Sierra Code - Transfer Case Clutch

What does this mean?

What are the Possible Causes of the DTC C0397 2018 GMC Sierra?

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 2018 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 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 2018 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 C0397 2018 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 C0397 2018 GMC Sierra Code

1. What does the OBDII code C0397 mean on a 2018 GMC Sierra?

C0397 indicates an issue with the transfer case clutch control circuit, which is responsible for engaging and managing the transfer case clutch in the vehicle's drivetrain.

2. What are the common symptoms of code C0397 in a 2018 GMC Sierra?

Symptoms may include difficulty shifting between 2WD and 4WD modes, 4WD system inoperability, warning lights on the dashboard, or unusual drivetrain noises.

3. What causes the C0397 code to appear in a 2018 GMC Sierra?

Possible causes include a faulty transfer case clutch actuator, damaged wiring or connectors in the clutch control circuit, or issues with the transfer case control module.

4. Can a bad transfer case control module trigger the C0397 code?

Yes, a malfunctioning transfer case control module can fail to send or interpret the correct signals, leading to this code.

5. How do I diagnose the C0397 code on my 2018 GMC Sierra?

Diagnosis involves inspecting the wiring and connectors for damage, testing the transfer case clutch actuator, and using a scan tool to monitor related sensor data and control signals.

6. Can I drive my 2018 GMC Sierra with the C0397 code active?

Driving with this code may be possible, but it could limit or disable 4WD functionality and cause additional damage if the issue is not resolved promptly.

7. How can I fix the C0397 code on a 2018 GMC Sierra?

Repairs may include replacing the faulty transfer case clutch actuator, repairing damaged wiring or connectors, or reprogramming/repairing the transfer case control module.

8. How much does it cost to fix the C0397 code on a 2018 GMC Sierra?

Repair costs vary depending on the specific issue but may range from $200 to $1,000, including parts and labor.

9. Is the C0397 code specific to the 2018 GMC Sierra?

No, the C0397 code can appear in other GMC vehicles with similar transfer case systems, but the exact causes and symptoms may vary.

10. How can I prevent the C0397 code from occurring again?

Regular maintenance, inspecting wiring for damage, and ensuring the transfer case system is properly lubricated can help prevent recurrence of this code.