C0310

DTC C0310

Circuit Description
The transfer case motor is a bi-directional, permanent magnet, DC motor. When energized through motor control A or motor control B, the ground is provided by the opposing motor control circuit, then grounded through the transfer case shift control module ground circuit The motor, through a series of gears, rotates a shaft which moves the mode and range forks to shift the transfer case between 4H, AUTO 4WD, 2H, N, and 4L ranges.

This DTC detects an open in the motor control A or motor control B circuits, or an open motor.

DTC Descriptor
This diagnostic procedure supports this DTC:
DTC C0310 Motor A/B Circuit Open

Conditions for Running the DTC
^ The ignition is ON.
^ The system voltage is 9 - 16 volts.

Conditions for Setting the DTC
^ The system tests the motor circuits by checking for unwanted voltage.
^ Then, the system supplies voltage on each of the motor circuits and reads the voltage back on the other circuit.
^ If the system detects a condition with the circuits, the DTC is logged. The transfer case shift control module senses a low voltage return in the motor control A or motor control B circuits when a high voltage is expected.

Action Taken When the DTC Sets
^ The SERVICE 4WD indicator remains illuminated for the remainder of the current ignition cycle.
^ All shifting is disabled.

Conditions for Clearing the DTC
^ The transfer case shift control module clears the DTC if the condition for setting the DTC no longer exists.
^ A history DTC clears after 100 consecutive ignition cycles without a fault present.
^ History DTCs can be cleared using a scan tool.

Test Description

Steps 1-9:

These numbers correspond to the step numbers on the diagnostic table.
2. This step listens for an audible motor noise when the encoder motor operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. This step tests the for a higher than normal resistance in the motor control A and B circuits and through the module.
4. This step tests the motor control A circuit for an open or high resistance.
5. This step tests the motor control B circuit for an open or high resistance.
6. This step tests for continuity across the motor circuit.