C0321
DTC C0321Circuit Description
The transfer case shift control module controls the transfer case lock solenoid.
The transfer case lock solenoid is released by being energized. This is accomplished by grounding the lock solenoid control circuit during gears shifts, and in the AUTO or adapt mode. Locking action is applied when power or ground are taken away from the lock solenoid, the transfer case motor is prevented from moving. In this manner, the system is capable of providing a 2HI, 41-11 and 4LO lock-up without the need of additional vehicle power to hold the transfer case In these positions.
This DTC detects an open lock solenoid coil, open motor lock control circuit, or an open motor lock feed circuit.
Conditions for Setting the DTC
^ The transfer case shift control module will try to unapply, turn OFF the lock solenoid by grounding the motor control circuit.
^ If the module does not sense the battery voltage at the motor lock control circuit prior to applying the motor lock, the DTC will set.
^ Transfer Case Lock output reads back as a high voltage when a low voltage is expected.
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 is not currently present.
^ 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 click when the encoder motor brake operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the lock solenoid feed side of the encoder motor lock solenoid.
4. Verifies that the lock solenoid battery positive circuit is not shorted to power, shorted to ground, or have high resistance.
5. Determines if the encoder motor lock solenoid is faulty by checking the internal resistance.
6. Tests the control circuit of the encoder motor brake for a short to voltage or an open.
7. Determines if a corroded or damaged connector in the encoder motor harness is the cause.
DTC C0321 (1 Of 2):
DTC C0321 (2 Of 2):
