NVG 236/246-NP8 Two-Speed Automatic

DTC C0327

Circuit Description

The transfer case encoder is a switch that converts a shaft position, representing a mode or range position, into electrical signals for use by the transfer case shift control module. The encoder houses 4 Hall effect sensors that are used for channels P, A, B, and C. These sensors provide a path to ground when a magnet, which is part of the shift rail, passes over them.

The transfer case shift control module supplies an 8-volt reference and a ground circuit for the encoder Hall effect sensors to function.

The transfer case shift control module supplies 5 volts on all the channels. As these channels are pulled to ground, the module can interpret the location of the transfer case shift position.

This DTC detects an open, short to ground, or a short to voltage in the encoder feed circuit, an open in the signal ground circuit, an open, short to ground, or short to voltage in the Encoder channel circuits.

Conditions for Setting the DTC

The transfer case shift control module reads back all high or low voltage on the Encoder channel circuits.

Action Taken When the DTC Sets

^ All motor activity will stop and the Transfer Case Lock engaged.
^ A default rail to rail shift may be allowed, toggle between 4H and 2H.
^ 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 no longer exists.
^ 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. This step determines if the transfer case control module is supplying the correct 8-volt reference
3. This step inspects for proper voltage on the four encoder signal circuits.
4. This step tests for an open or high resistance on the encoder signal ground circuit.
5. This step tests the encoder signal circuits for an open, short to ground, or short to power.
6. This step inspects for a binding sector shaft.
7. This step disassembly and overhaul for a binding sector shaft.