DTC 003
DTC 003Test 1-10:
Test 11-18:
Circuit Description
This code indicates that the transfer case encoder motor circuits are not functioning properly. One of the following conditions may exist.
^ One of the internal power relays in the Transfer case control module (TCCM) is not energizing or de-energizing.
^ An open exists in the Battery Positive Voltage, Ground, Motor Control A or Motor Control B circuits.
^ A short to ground exists in the Battery Positive Voltage, Motor Control A or Motor Control B circuits.
^ A short exists within the motor or TCCM.
The transfer case encoder motor has a bidirectional, permanent magnet, D.C. motor. When a shift request is made by the TCCM, voltage will be applied through one of the motor control circuits and the TCCM will provide the ground through the other motor circuit. When a shift is requested in the opposite direction, the TCCM will reverse polarity on these two circuits. The motor through a series of gears, rotates a shaft which moves the mode and range forks to shift the transfer case between gears.
Action Taken When the DTC Sets
The TCCM utilizes an error counting system when setting this code. When the TCCM detects a circuit error, the counter will log a count of 4. When the system operates correctly, the counter will reduce by a count of 1. A total count of 32 must be reached in order for DTC 003 to be set. The system must malfunction at least 25 percent of the time in order for a DTC 003 to be set. It is imperative that the technician test drive the vehicle and request several shifts in order for this code to be properly logged.
In the event that one of the internal TCCM power relays is stuck in the energized state, the TCCM will energize the other motor control circuit to keep the motor from running. All of the transfer case control switch indicators will flash continuously to prompt the driver that service is required. The transfer case system will be disabled and the TCCM power relays will remain energized even with the ignition in the OFF position. This may cause the battery to discharge. Any other condition that sets a DTC 003 will not follow this routine but a fault code will be stored.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present and a momentary loss of battery power at the battery positive voltage circuit.
Test Description
The numbers refer to the step numbers on the diagnostic table.
2. This step tests the power control relays inside the TCCM.
3. This step tests for voltage to the ATC/4WD fuse.
4. This step tests the ATC/4WD fuse.
5. This step tests for a voltage polarity change at the motor.
6. This step tests for voltage at circuit 16 Battery Positive Voltage.
7. This step tests for continuity to ground at circuit Ground.
8. This step tests for continuity on motor control A and B circuits.
9. This step tests for a grounded or shorted motor.
10. This step tests for a short to ground on circuit 16 Battery Positive Voltage.
11. This step tests for a short to ground on circuits Motor Control A and Motor Control B.