2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 889

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 889

Diagnostic Aids

* It is possible to have windings inside the motor shorted to the case resulting in a short to ground causing this DTC to set.

* The default actions for C0321 may set C0306.

* EL-49741 - harness is a good source for 9 V.

* EL-49742 - harness is a good source for B+ and ground.

* The transfer case drain plug is a good source for ground.

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

Special Tools

* EL-49741 - 9 V+ Power Source Harness

* EL-49742 - Battery Voltage B+ and Ground Source Harness

* J 35616 - GM-Approved Terminal Test Kit

Circuit/System Testing

1. Verify that the TREC fuse, and the Miscellaneous IGN fuse, underhood fuse block, are NOT open.

瀚慖f the TREC fuse is OPEN, test the battery positive voltage, TCCM Harness X3 pin C, for a short to ground.

瀚慖f the Miscellaneous IGN fuse is OPEN, test the Ignition 1 voltage circuit, TCCM harness X2 pin 6, for a short to ground.

2. Ignition ON, engine OFF.

3. With a scan tool, check DTC's. If DTC C0321 is set, go to C0321.

4. Disconnect the X1 harness connector at the transfer case encoder motor (TCEM).

Note: When test probing harness terminals, it is imperative to use the proper test probe from the most current version of the J 35616 - Kit.

Use of an improper test probe may deform the terminal, resulting in intermittent open conditions.

5. Using the PU probe J 35616-4A, test for a 1.0-2.5 V diagnostic voltage between the motor B circuit, TCEM X1 pin D, and a good ground.

瀚慖f the voltage is greater than the specified range, test the motor B circuit for a short to voltage. If all circuits and connections test normal,

test the TCCM.

瀚慖f the voltage is less than the specified range, test the motor B circuit for an open/high resistance or short to ground. If all circuits and

connections test normal, test the TCCM.

6. Using the PU probes J 35616-4A, test for B+ (+0.0/-1.0 V) between the motor A circuit, TCEM harness X1 pin A, and a good ground.

瀚慖f the voltage is less than the specified range, test the motor A circuit for an open/high resistance, short to ground or short together

condition. If all circuits and connections test normal, test the TCCM.

7. Remove the encoder motor from transfer case. Using a paint pen or marker, place indexing marks on the encoder motor drive gear and the

mounting surface of the encoder motor.

8. Connect the X1 connector at the transfer case encoder motor (TCEM). Position the TCEM so that the indexing marks are visible from the

side of the vehicle.

9. Remove key. Wait 30 seconds. Key ON, engine OFF. Clear codes.

10. Block wheels. Parking brake engaged. Transmission in Neutral. Using the Transfer Case Motor Control function of the Special Function

feature of the scan tool, command the encoder motor forward and reverse. When commanded forward the encoder motor drive gear should