Test Description

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2. This step determines if the rear propshaft speed sensor and wiring are operating properly.
3. This step determines if the front propshaft speed sensor and wiring are operating properly.
4. This step determines if the motor control A or motor control B circuit are shorted to ground within the encoder motor.
5. This step tests the integrity of the motor windings.
6. This step tests the motor control A and motor control B circuits for an open, short to ground, or high resistance between the encoder motor and the transfer case shift control module.
7. This step determines whether the transfer case is mechanically functioning properly.

Fig 1: DTC C0374 (Steps 1-4)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC C0374 (Steps 5-11)

Courtesy of GENERAL MOTORS CORP.