DTC 001

DTC 001
Circuit Description

The transfer case shift control module (TCCM) normally has battery voltage supplied through the battery positive voltage circuit at all times. When the ignition is ON, the TCCM conducts a self-test. This self-test determines if the current memory is the same memory that was retained when the ignition was last turned OFF. This self-test indicates whether the random access memory (RAM) standby power-supply to the TCCM pin C6 was interrupted. If the power is interrupted, the diagnostic trouble codes (DTCs) would be cleared from memory. If the self-test fails, the TCCM sets DTC 001.

DTC Descriptor
This diagnostic procedure supports this DTC:
DTC 001 RAM Standby Power Supply Failure

Conditions for Clearing the DTC
This DTC will clear when the voltage supply failure has been corrected and the ignition switch has been cycled 5 times.

Test Description

Steps 1-7:

These numbers correspond to the step numbers on the diagnostic table.
2. This step inspects the CTSY LP fuse for an open.
3. This step tests the battery positive voltage circuit for an open or high resistance.
4. This step rechecks the CTSY LP fuse for an open.
5. This step tests the battery positive voltage circuit for a short to ground.