C0327

DTC C0327

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.



DTC Descriptor
DTC C0327
- Encoder Circuit Malfunction




Circuit/System Description

The transfer case shift control module has four encoder channels, P, C, A, and B, which are supplied 5 volts each. The four encoder channels each run to a switch located inside the encoder/motor assembly. When a particular encoder channel is active the switch is closed and 5 volts flows through the encoder signal return circuit. If the module wants to request motor position a low side driver pulls the voltage low on the encoder signal return and the corresponding channel circuit indicating motor position.


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


This DTC detects an open, high resistance, or a short to voltage, in the encoder signal return circuit, or an open, high resistance, or short to voltage in the encoder channel circuits.


Conditions for Running the DTC

* The ignition is ON.
* The system voltage is 9-18 volts.



Conditions for Setting the DTC

The transfer case shift control module reads back a high voltage when a low voltage is expected, or low voltage when a high voltage is expected on the encoder channel circuits, or the encoder signal return circuit.


Action Taken When the DTC Sets

* All motor activity will stop.
* All the transfer case shift control switch mode indicators will be commanded OFF.
* The SERVICE 4WD indicator will be latched on for the remainder of the current ignition cycle.
* If a new mode is requested while the DTC is present either current or history, the indicator for the mode requested will flash for 15 seconds and then go out.



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 33 consecutive ignition cycles without a fault present.
* History DTCs can be cleared using a scan tool.



Reference Information
Schematic Reference

Transfer Case Control Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Component Connector End Views)
Description and Operation

Transfer Case Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information.


Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.