2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 897

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 897

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 Verification

1. Key ON, engine OFF.

2. Connect a scan tool.

3. Parking brake engaged. Transmission in Neutral.

4. Using the Transfer Case Lock function of the Special Function feature of the scan tool, command the transfer case lock ON and OFF. You

should be able to hear the encoder motor lock engage and disengage.

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. 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.

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

ground.

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

circuits and connections test normal, test the TCCM.

5. Using the PU probe J 35616-4A, test for a 4.0-5.0 V diagnostic voltage between the lock solenoid control circuit, TCEM X1 pin C, and a

good ground.

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

connections test normal, test the TCCM.

6. Test the TCEM.

Component Testing

Transfer Case Encoder Motor (TCEM) - Actuator Lock, Motor A and Motor B

1. 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.

2. Install EL-49742 - harness.

3. Using a PU probe J-35616-5, attach the red lead from the EL-49742 - jumper harness to the motor control A terminal of the TCEM, pin A.

4. Using a PU probe J-35616-5, touch the black lead from this same jumper harness to the motor control B terminal of the TCEM, pin D. The

encoder motor drive gear should not rotate.

瀚慖f the encoder motor rotates, replace the encoder motor.

5. Using a PU probe J-35616-5, attach the red lead from the EL-49741 - harness to the battery positive voltage terminal of the TCEM harness,

pin B.

6. Using a PU probe J-35616-5, attach the black lead from this same jumper harness to the lock solenoid control terminal of the TCEM harness,

pin C.

7. Attach a 9-volt battery to this harness (not included). You should hear the encoder motor unlock.

瀚慖f you do not hear the TCEM unlock, test the affected circuits of the TCEM harness for an open/high resistance, short to ground or short

together. If all circuits and connections test normal, replace the TCEM.

8. Touch the black lead from EL-49742 - jumper harness to the motor control B terminal of the TCEM, pin D. The encoder motor drive gear

should rotate.

瀚慖f the encoder motor drive gear does not rotate, replace the encoder motor.