C0309

DTC C0309

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 a short to voltage in the motor control A or motor control B circuits, or a shorted motor.

DTC Descriptor
This diagnostic procedure supports this DTC:
DTC C0309 Motor A/B Circuit High

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

Conditions for Setting the DTC
^ The system tests the motor circuits by reading the voltage on each circuit.
^ If the system detects a condition with the circuits, the DTC is logged.
^ The transfer case shift control module senses a high voltage in the motor control A or motor control B circuits when a low 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 1-8:

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 motor control A or the transfer case shift control module for a short to voltage.
4. This step tests motor control B or the transfer case shift control module for a short to voltage.
5. This step tests motor control A circuit for a short to voltage.
6. This step tests motor control B circuit for a short to voltage.