AutoCodes – GMC – C0387 2017 GMC Sierra

C0387 2017 GMC Sierra Code - Unable to Complete Shift

Quick Answer

The Transfer Case Motor, also known as the transfer case range actuator, is a bi-directional, permanent magnet, DC motor. 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: C0387 2017 GMC Sierra indicates Unable to Complete Shift.
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 266

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 C0387 2017 GMC Sierra Description

The Transfer Case Motor, also known as the transfer case range actuator, is a bi-directional, permanent magnet, DC motor. When energized, through the transfer case clockwise circuit or transfer case counterclockwise circuit, the ground is provided by the opposing motor control circuit which becomes grounded through the transfer case control module ground circuit. The transfer case range actuator, through a series of gears, rotates the transfer case control actuator shaft which moves the transfer case two/four-wheel drive actuator cam and transfer case high/low shift fork in order to shift the transfer case between the following modes or ranges: 2WD, 4WD/AWD Automatic, 4WD High/Locked, 4WD Low, Neutral.
If the shift lever detent shaft were to bind, or there was a mechanical failure, or the transfer case clockwise circuit and the transfer case counterclockwise circuit were shorted together, the shift would not be completed. This will cause the Diagnostic Trouble Code (DTC) to be set in order to protect system components from damage.

OBDII Code C0387 2017 GMC Sierra - Unable to Complete Shift - AutoCodes.com — C0387 2017 GMC Sierra Code - Unable to Complete Shift

What does this mean?

What are the Possible Causes of the DTC C0387 2017 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

How to Fix the DTC C0387 2017 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 C0387 2017 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 C0387 2017 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 C0387 2017 GMC Sierra Code

1. What are the common symptoms of OBDII code C0387 in a 2017 GMC Sierra?

The common symptoms of OBDII code C0387 "Unable to Complete Shift" in a 2017 GMC Sierra may include difficulty shifting gears, transmission slippage, and the transmission not engaging properly.

2. What could be causing the OBDII code C0387 in a 2017 GMC Sierra?

The OBDII code C0387 in a 2017 GMC Sierra is typically caused by issues with the transmission shift solenoid, a faulty transmission control module (TCM), low transmission fluid levels, or mechanical problems within the transmission.

3. How can I diagnose the OBDII code C0387 in my 2017 GMC Sierra?

To diagnose the OBDII code C0387 in a 2017 GMC Sierra, you can use an OBDII scanner to retrieve the trouble codes, inspect the transmission fluid level and condition, check for any visible damage or leaks in the transmission system, and perform a thorough inspection of the shift solenoid and TCM.

4. What are some repair tips for fixing the OBDII code C0387 in a 2017 GMC Sierra?

Repair tips for fixing the OBDII code C0387 in a 2017 GMC Sierra may include replacing the faulty shift solenoid, repairing or replacing the TCM, ensuring the transmission fluid is at the correct level and in good condition, and addressing any mechanical issues within the transmission.

5. Can I continue driving my 2017 GMC Sierra with the OBDII code C0387?

It is not recommended to continue driving your 2017 GMC Sierra with the OBDII code C0387 "Unable to Complete Shift" as it can lead to further damage to the transmission system. It is best to address the issue promptly to prevent more serious problems.

6. How much does it typically cost to repair the OBDII code C0387 in a 2017 GMC Sierra?

The cost of repairing the OBDII code C0387 in a 2017 GMC Sierra can vary depending on the exact cause of the issue and the extent of the repairs needed. It is advisable to consult a professional mechanic for an accurate diagnosis and cost estimate.

7. Are there any recalls or technical service bulletins related to the OBDII code C0387 in a 2017 GMC Sierra?

It is advisable to check with the manufacturer or a GMC dealership to see if there are any recalls or technical service bulletins related to the OBDII code C0387 in a 2017 GMC Sierra. They may have information on known issues and potential remedies.

8. What steps should I take if the OBDII code C0387 keeps coming back in my 2017 GMC Sierra after repairs?

If the OBDII code C0387 keeps coming back in your 2017 GMC Sierra after repairs, it is important to recheck the repairs that were done, ensure all components were properly installed and functioning, and consider seeking a second opinion from a qualified mechanic to address any underlying issues.

9. Can a DIY enthusiast repair the OBDII code C0387 in a 2017 GMC Sierra?

While some DIY enthusiasts may have the skills and tools to attempt repairs related to the OBDII code C0387 in a 2017 GMC Sierra, it is a complex issue that may require specialized knowledge and equipment. It is generally recommended to consult a professional mechanic for proper diagnosis and repair.

10. How can I prevent the OBDII code C0387 from occurring in my 2017 GMC Sierra in the future?

To prevent the OBDII code C0387 from occurring in your 2017 GMC Sierra in the future, it is important to perform regular maintenance on the transmission system, check and maintain proper fluid levels, address any issues promptly, and drive your vehicle responsibly to reduce wear and tear on the transmission components.