Circuit Description
The transfer case encoder motor is a permanent magnet D.C. motor and gear reduction assembly. The encoder motor is controlled with a Pulse Width Modulated (PWM) circuit within the transfer case shift control module. This circuit consists of a power supply relay (Motor A) circuit that supplies voltage to the motor through CKT 1552. The Motor B circuit (CKT 1553) is a PWM driver that varies the duty cycle to control the amount of current through the motor to ground.
This DTC detects a short to power on circuits 1552 and 1553.
Conditions for Setting the DTC
| • | The system will test the motor circuits by checking for unwanted voltage. |
| • | The system supplies voltage on the Motor A circuit and reads the voltage back on the Motor B circuit. |
| • | The transfer case shift control module senses a high voltage return on circuits 1552 or 1553 when a low voltage is expected. |
| • | If the system detects a problem with the circuits, the DTC is logged. |
Action Taken When the DTC Sets
| • | All clutch activation (slip control) will be disabled. |
| • | The SERVICE indicator (AWD/4WD) lamp will be latched on for the remainder of the current ignition cycle. |
Conditions for Clearing the DTC
| • | Current DTC |
| The transfer case shift control module will clear the DTC if the condition for setting the DTC no longer exists. |
| • | History DTC |
| - | Once 100 consecutive ignition cycles without a fault present. |
| - | A scan tool CLEAR CODES command. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table:
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Transfer Case Diagnostic System Check performed? | -- | Go to Step 2 | |
Is the voltage reading greater than the specified value? | 0 V | Go to Step 3 | Go to Step 5 | |
3 |
Is the voltage reading greater than the specified value? | 0 V | Go to Step 4 | Go to Step 6 |
4 | Repair a short to voltage in CKT 1552. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 7 | -- |
5 | Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement . Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 7 | -- |
6 | Repair a short to voltage in CKT 1553. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 7 | -- |
7 |
Are all the ATC components connected and properly mounted? | -- | Go to Step 8 | -- |
8 | Clear all ATC DTCs. Are all the ATC DTCs cleared? | -- | -- |
