AutoCodes – GMC – C0374 GMC

C0374 GMC Code - Transfer Case System Malfunction

Quick Answer

The transfer case shift control module senses rear slip. Common causes include Faulty Transfer Case Motor/Encoder, Transfer Case Motor/Encoder harness is open or shorted, Transfer Case Motor/Encoder 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: C0374 GMC indicates Transfer Case System Malfunction.
Common causes: Common causes include Faulty Transfer Case Motor/Encoder, Transfer Case Motor/Encoder harness is open or shorted, Transfer Case Motor/Encoder 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 3,919

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 Jun 26, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code C0374 GMC Description

The transfer case shift control module senses rear slip. After several attempts of applying torque to the front wheels, by activating the encoder motor, the transfer case still sees a difference in speed between the front propshaft speed sensor and rear propshaft speed sensor. The transfer case shift control module is unable to correct sensed wheel slip for 10 consecutive seconds.

OBDII Code C0374 GMC - Transfer Case System Malfunction - AutoCodes.com — C0374 GMC Code - Transfer Case System Malfunction

What does this mean?

What are the Possible Causes of the DTC C0374 GMC?

Faulty Transfer Case Motor/Encoder
Transfer Case Motor/Encoder harness is open or shorted
Transfer Case Motor/Encoder circuit poor electrical connection

How to Fix the DTC C0374 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

There is factory service bulletin with the following information:

The speed sensor signal may have become corrupted. Possible openings in the speed sensor wire insulation (twisted pairs) can allow water intrusion. Also, wire connections contaminated by water may result in short circuits and erroneous speed sensor readings. This most often occurs on the rear speed sensor circuit.

Correct problem by inspecting the wiring harness to the transfer case speed sensors. Completely inspect and test all wiring. Replace the affected twisted pairs.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C0374 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 C0374 GMC code?

Need more information on how to fix the C0374 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C0374 GMC code diagnosed by a professional: Find a repair shop in your area

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 C0374 GMC Code

1. What are the common symptoms of OBDII code C0374 GMC indicating a Transfer Case System Malfunction?

- Common symptoms include difficulty shifting gears, strange noises from the transfer case, and the "Service 4WD" warning light illuminated on the dashboard.

2. What are the possible causes of OBDII code C0374 GMC?

- The code C0374 GMC can be triggered by issues with the transfer case shift control module, faulty wiring, damaged connectors, or a malfunctioning transfer case motor.

3. How can I diagnose the cause of OBDII code C0374 GMC?

- Diagnosing the code typically involves using a professional OBDII scanner to retrieve the specific error codes, checking the wiring and connectors for any damage, and testing the transfer case shift control module and motor for proper functionality.

4. Can I still drive my vehicle with OBDII code C0374 GMC present?

- It is not recommended to drive your vehicle with the OBDII code C0374 GMC present, as it can lead to further damage to the transfer case system and affect the drivability of the vehicle.

5. How can I repair OBDII code C0374 GMC related to a Transfer Case System Malfunction?

- Repairing the code C0374 GMC may involve replacing the transfer case shift control module, repairing or replacing damaged wiring and connectors, or replacing the transfer case motor if necessary.

6. Are there any DIY tips for addressing OBDII code C0374 GMC?

- DIY tips include checking the transfer case fluid level, inspecting for any visible damage to wiring and connectors, and ensuring proper connections to the transfer case shift control module.

7. How much does it typically cost to repair OBDII code C0374 GMC?

- The cost of repairing OBDII code C0374 GMC can vary depending on the specific issue causing the malfunction, but it may range from $200 to $800 for parts and labor.

8. Can weather conditions affect the occurrence of OBDII code C0374 GMC?

- Extreme weather conditions, such as excessive heat or cold, can potentially impact the performance of the transfer case system and contribute to the triggering of code C0374 GMC.

9. Is it necessary to reset the OBDII code C0374 GMC after completing repairs?

- Yes, it is important to clear the OBDII code C0374 GMC after completing repairs to reset the system and ensure that the issue has been properly addressed.

10. How often does OBDII code C0374 GMC occur in GMC vehicles?

- OBDII code C0374 GMC related to a Transfer Case System Malfunction is a relatively common issue in GMC vehicles, particularly in models equipped with 4WD systems.