2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 665

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 665

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 Testing

1. Ignition OFF, disconnect the low beam headlamp relay.

2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.

瀚慖f the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify that a test lamp illuminates between the B+ circuit terminal 85 and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the

B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground. If the circuit tests normal, test or replace the low beam

headlamp relay.

4. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground.

瀚慖f the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

5. Disconnect the harness connector at the appropriate head lamp.

6. Test for less than 5 ohm between the head lamp ground circuit terminal listed below and ground:

* With X88 - Terminal A

* With Z88 - Terminal B

瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.

7. Connect the harness connector at the headlamp.

8. Connect a 20 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the headlamp is activated.

瀚慖f the headlamp does not activate and the circuit fuse is good, test the control circuit for an open/high resistance. If the circuit tests

normal, test or replace the headlamp.

瀚慖f the headlamp does not activate and the circuit fuse is open, test the control circuit for a short to ground. If the circuit tests normal, test

or replace the headlamp.

9. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.

10. Command the Low Beams ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded

states.

瀚慖f the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

瀚慖f the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace

the BCM.

11. If all circuits test normal, test or replace the low beam headlamp relay.

Repair Instructions

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

* Relay Replacement (Attached to Wire Harness) (See: Power and Ground Distribution/Power Distribution Relay/Service and Repair/Relay

Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (See: Power and Ground Distribution/Power

Distribution Relay/Service and Repair/Relay Replacement (Within an Electrical Center))

* Headlamp Replacement (Cadillac Escalade) (See: Lighting and Horns/Headlamp/Service and Repair/Removal and Replacement/Headlamp

Replacement (Cadillac Escalade))Headlamp Replacement (GMC Yukon Two-mode Hybrid) (See: Lighting and Horns/Headlamp/Service

and Repair/Removal and Replacement/Headlamp Replacement (GMC Yukon Two-mode Hybrid))Headlamp Replacement (Yukon) (See:

Lighting and Horns/Headlamp/Service and Repair/Removal and Replacement/Headlamp Replacement (Yukon))Headlamp Replacement

(Chevrolet Tahoe Two-mode Hybrid) (See: Lighting and Horns/Headlamp/Service and Repair/Removal and Replacement/Headlamp