Circuit Description
This symptom indicates that the transfer case encoder motor circuits are not functioning properly. This symptom is similar to DTC 003 but differs because the counter inside the transfer case control module (TCCM) has not yet set DTC 003. One of the following conditions may exist.
| • | One of the internal power relays in the (TCCM) is not energizing or deenergizing. |
| • | 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 bi-directional 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 control 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.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Transfer Case Control Schematics | ||||
1 |
Important: The transfer case shift control module is not a class 2 device, and therefore a scan tool can not be utilized on this transfer case. Did you perform A Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check |
Does the transfer case complete all mode and range shifts? | -- | Go to Intermittents and Poor Connections Diagnosis in Wiring Systems | Go to DTC 003 | |
