C0374 on Chevrolet: How to Diagnose & Fix
Transfer Case / Automatic 4WD System Malfunction (manufacturer-specific)
1 Chevrolet model · 1 documented issue · $250-$1,200 repair
C0374 on Chevrolet by model: symptoms, diagnosis and fix
Silverado 1500 trucks equipped with electronic shift transfer cases commonly develop failures in the transfer case encoder motor, mode position sensor, or related switch/module circuitry. Owners report the truck getting stuck in 2HI, 4HI, or 4LO, flashing selector lights, or displaying a Service 4WD message. GM service information and large numbers of owner complaints/forum reports document the issue across both GMT800 and GMT900 trucks.
Common Symptoms
- Service 4WD message
- 4WD selector lights flashing
- stuck in 2HI or 4HI
- will not shift into or out of 4LO
- unexpected neutral condition in transfer case
- intermittent four-wheel-drive operation
How to Fix
Diagnosis should include checking transfer case switch inputs, encoder motor operation, transfer case control module communication, power/ground integrity, and corrosion at connectors. Repair often involves replacing the encoder motor assembly, dash 4WD selector switch, or reprogramming/replacing the transfer case control module if faults persist. Fluid condition and transfer case internal binding should also be ruled out before parts replacement.
Sources for this issue (1)
C0374 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C0374 mean on a Chevrolet?
C0374 stands for "Transfer Case / Automatic 4WD System Malfunction (manufacturer-specific)." C0374 is a manufacturer-specific chassis code (commonly seen on GM four-wheel-drive vehicles) that generally indicates a general malfunction in the transfer case / automatic four-wheel-drive control system. When it sets, the Auto 4WD mode is typically unavailable and a 'Service 4WD' message may appear. Because the exact subsystem can vary by maker and model, the precise fault should be confirmed with a factory-level scan tool. This code affects drivetrain/4WD operation rather than braking. On Chevrolet it is documented across 1 model: Silverado 1500.
What are the most common causes of C0374?
The most common causes of C0374 are: Faulty transfer case control module, Transfer case encoder/actuator motor fault, Damaged wiring or connectors in the 4WD circuit, Mode-select switch fault, Low system voltage or poor ground, Mechanical fault within the transfer case, Software/calibration issue in the 4WD module. The specific cause varies by vehicle.
How much does it cost to fix C0374 on a Chevrolet?
Published repair estimates on Chevrolet range from $250 to $1,200 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for C0374 on a different make?
View C0374 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.