2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 940

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 940

Circuit/System Description

The transfer case incremental position sensor (IPS) and the transfer case two/four wheel drive actuator position sensor, also known as the rotational

position sensor (RPS), both send transfer case mode/range position information to the transfer case shift control module (TCCM). Both sensors

send this information as voltage signals which are converted to degrees by the TCCM software. If the two sensors disagree by greater than a

predetermined amount the DTC will set.

The IPS is more sensitive than the RPS, but needs to reference the RPS value at key-up and mode changes. The IPS is an integral part of the

transfer case actuator and cannot be replaced independently.

The RPS is an absolute sensor and is an independently replaceable part. The TCCM syncs the IPS with the RPS at key-up and mode changes.

Conditions for Running the DTC

* Ignition ON.

* System voltage 10.5-18 V.

Conditions for Setting the DTC

The incremental sensor and the rotational position sensor are both showing valid positions, but differ by greater than a predetermined amount when

NO mode change is in progress.

Action Taken When the DTC Sets

* Shifting disabled.

* The SERVICE 4WD indicator remains illuminated for the remainder of the current ignition cycle.

Conditions for Clearing the DTC

* The TCCM clears the DTC once the conditions for setting the DTC are no longer present.

* A history DTC clears after 40 consecutive warm up cycles without a fault present.

* History DTCs can be cleared using a scan tool.

Diagnostic Aids

* The incremental position sensor and the rotational position sensor both show position in degrees. Monitor these parameters for erratic or

unreasonable readings.

* A Key ON, engine OFF sequence with transfer case encoder motor removed, but still attached to the harness, will cause C0398 5A to set.

Reference Information

Schematic Reference

Transfer Case Control Schematics (See: Transmission and Drivetrain/Transfer Case/Diagrams/Electrical Diagrams/MP 3023/3024-NQH -

Transfer Case)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information.

Circuit/System Verification

1. Key ON, engine OFF.

2. Connect a scan tool.

3. Monitor the IPS and RPS parameters on the scan tool. Using the transfer case shift control switch, shift the transfer case into all modes. The

IPS and RPS parameters should track each other.