C0315

DTC C0315





Circuit Description
The transfer case motor is a bidirectional, permanent magnet, D.C. motor. When energized, the motor, through a series of gears, rotates a shaft which moves the mode, and the range forks to shift the transfer case. The transfer case shifts between 4H, AUTO 4WD, 2H, N. and 4L ranges. The motor becomes energized through motor control A, or through motor control B. The ground is provided by the opposing motor control circuit, and then grounded through the transfer case shift control module ground circuit.
This DTC detects an open in the module ground circuit.

Conditions for Setting the DTC
The system test the motor circuits:
^ First, the system checks for unwanted voltage.
^ Then, the system supplies voltage on each of the motor circuits and reads the voltage back on the other circuit.
^ After the system checks for opens and shorts on the motor circuits, its applies voltage through the motor and back to the module to ground.
^ If the system detects a high voltage on the ground circuit, the DTC is logged.

Action Taken When the DTC Sets
^ All shifting will be disabled.
^ 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. Listen for an audible motor noise when the encoder motor operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests the motor ground circuit for an open.