C0387 on Chevrolet
Manufacturer-Specific Chassis Code (commonly transfer case / shift-related on GM)
C0387 on Chevrolet vehicles indicates manufacturer-specific chassis code (commonly transfer case / shift-related on gm). Au7o has documented this code across 2 Chevrolet models — most commonly on Colorado, Silverado 2500HD. C0387 is a manufacturer-specific chassis code that falls in a range largely reserved/non-standardized under SAE, so its exact meaning varies by manufacturer. On many GM vehicles it appears alongside transfer-case encoder/shift codes and is generally associated with an inability to complete a requested shift or a related transfer-case/electronic shift fault. Because the precise definition is not standardized, the code should be confirmed against the specific vehicle's service information. In general it points to a chassis driveline or shift-control concern rather than the engine itself. Typical repair costs on Chevrolet range from $100 to $700, depending on the specific model and root cause.
Common Causes of C0387
- •Transfer case encoder motor or shift fault (GM applications)
- •Damaged or corroded wiring/connectors in the affected circuit
- •Failed shift motor or actuator
- •Control module (e.g., transfer case control module) fault
- •Low system voltage or poor ground
- •Mechanical binding in the shift mechanism
C0387 on Chevrolet by Model
Chevrolet Colorado(1 issue)
- Front Axle Disconnect Actuator Failure Causing "Service 4WD" and No Front-Axle Engagement2004-2022
On four-wheel-drive Colorados the front axle uses an electric disconnect actuator on the front differential housing that must engage before the transfer case will complete a shift into 4HI/4AUTO/4LO. The actuator's motor, position sensor, and its exposed connector sit low on the axle where they take road spray, salt, and mud. Owners report the dash showing "Service 4WD", the 4WD selector lights blinking and then reverting to 2WD, and the truck driving in two-wheel drive despite the transfer case shifting. C0387 is the code most often stored. This is distinct from transfer case encoder motor failure: forum diagnosis threads repeatedly find the transfer case shifted correctly while the front axle actuator, its connector, or the chafed harness running to it was the actual fault. Reported on the 2004-2012 GMT355 trucks and again on the 2015-2022 generation, and it is much more common in road-salt states.
Chevrolet Silverado 2500HD(1 issue)
- Transfer Case Encoder Motor Failure1999-2025
The transfer case encoder motor on the Silverado 2500HD (NP246/NP261/NP263 transfer cases) fails, preventing the vehicle from shifting between 2WD, 4WD High, and 4WD Low. The encoder motor is mounted on the outside of the transfer case and uses an electric motor with a position sensor to actuate the shift fork. Moisture ingress, corrosion, and worn motor brushes cause intermittent or complete failure. The "Service 4WD" message appears on the DIC, and the transfer case may get stuck in one mode. Failure is more common in salt-belt states.
Looking for C0387 on a different make?
View C0387 across all makes →Frequently Asked Questions
What does C0387 mean on Chevrolet?▼
C0387 stands for "Manufacturer-Specific Chassis Code (commonly transfer case / shift-related on GM)." C0387 is a manufacturer-specific chassis code that falls in a range largely reserved/non-standardized under SAE, so its exact meaning varies by manufacturer. On many GM vehicles it appears alongside transfer-case encoder/shift codes and is generally associated with an inability to complete a requested shift or a related transfer-case/electronic shift fault. Because the precise definition is not standardized, the code should be confirmed against the specific vehicle's service information. In general it points to a chassis driveline or shift-control concern rather than the engine itself. On Chevrolet specifically, this code is documented across 2 models.
What causes C0387 on Chevrolet vehicles?▼
Common causes on Chevrolet: Transfer case encoder motor or shift fault (GM applications), Damaged or corroded wiring/connectors in the affected circuit, Failed shift motor or actuator, Control module (e.g., transfer case control module) fault, Low system voltage or poor ground. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix C0387 on a Chevrolet?▼
Repair costs on Chevrolet range from $100 to $700, depending on the specific model and root cause.
Which Chevrolet models have C0387 documented?▼
Au7o has documented C0387 on 2 Chevrolet models: Colorado, Silverado 2500HD.