C0374

DTC C0374





Circuit Description
The transfer case shift control module senses rear to front slip, a difference of rear to front wheel speed, and attempts to correct the difference by activating the encoder motor, to apply more torque to the front wheels.

Conditions for Setting the DTC
The transfer case shift control module is unable to correct sensed slip for 10 consecutive seconds.

Conditions for Clearing the DTC
^ A history DTC will clear after 100 consecutive ignition cycles without a fault present.
^ Use a scan tool in order to clear history and current DTCs.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. Helps determine if the DTC set due to a mechanical or an electrical fault.
3. Tests the integrity of the Motor Control circuit.
4. Determines whether the Encoder Motor is moving to the proper position.





DTC C0374

DTC C0376
Circuit Description
The front and rear propshaft speed sensor is a permanent magnet (PM) generator. The PM generator produces a pulsing AC voltage. The AC voltage level and number of pulses increases as speed increases. The module converts the pulsating AC voltage to a propshaft RPM which is used for calculations. The module only looks at these inputs together when the vehicle is in 4H, 4L, and AUTO 4WD range only. The propshaft RPM can be displayed with a scan tool. This DTC detects greater than 20 percent difference in the speed sensor inputs.

Conditions for Setting the DTC
The transfer case shift control module detects continued readings of front and rear propshaft speed signal which do not match. The module is unable to determine propshaft speed. The system will log the DTC if the front and rear propshaft inputs indicates a speed greater than 20 percent difference for 40 seconds while all of the following are true:
^ Transmission is NOT in Park/Neutral
^ Engine is running
^ Front axle is engaged
^ Front propshaft indicates speed less than 120 km/h (75 mph)
^ Front propshaft or rear propshaft speed exceeds 512 RPM
^ Vehicle Speed On Class 2 Data bus exceeds 16 km/h (10 mph)

Action Taken When the DTC Sets
^ All shifts to AUTO 4WD mode will be disabled. If the current mode is AUTO 4WD, the system will not allow any further adaptive events (correct wheel slip).
^ The SERVICE 4WD indicator will be latched on for the remainder of the current ignition cycle.

Conditions for Clearing the DTC
^ The transfer case shift control module will clear the DTC if the condition for setting the DTC does not exist.
^ A history DTC will clear after 100 consecutive ignition cycles without a fault present.
^ History DTCs can be cleared using a scan tool.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. Helps determine if the transfer case speed sensors are working properly.
3. Tests to see if the DTC will reset.
4. Inspects for mismatches and whether speed sensors are wired correctly.
5. Inspects the transfer case for mechanical failures.