2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1002

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 1002

compressor relay fault is detected, the ESCM retries the output every 15 seconds to try to recover from the fault.

Reference Information

Schematic Reference

Automatic Level Control Schematics (See: Steering and Suspension/Suspension/Suspension Control ( Automatic - Electronic

)/Diagrams/Electrical Diagrams/Automatic Level Control)

Connector End View Reference

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

Description and Operation

Automatic Level Control Description and Operation (See: Steering and Suspension/Suspension/Suspension Control ( Automatic - Electronic

)/Description and Operation/Automatic Level Control Description and Operation)

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

Ignition ON, command the compressor relay ON with a scan tool. Listen for the operation of the ALC relay and the automatic level control

compressor.

Circuit/System Testing

1. Ignition OFF, disconnect the ALC relay.

2. Ignition ON, verify that a test lamp does not illuminate between the relay connector control circuit terminal 86 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 relay connector 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 relay coil B+ circuit for a short to ground. If all circuits test normal, test or replace the ELC relay.

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

瀚慖f the test lamp does not illuminate, test the B+ circuit for an open/high resistance. If the circuit tests normal and the B+ circuit fuse is

open, test the relay coil B+ circuit and compressor control circuit for a short to ground or a faulty ALC compressor motor. If all circuits

test normal, test or replace the ELC relay.

5. Disconnect the harness connector at the air compressor.

6. Test for less than 1 ohm of resistance between the ALC compressor ground circuit terminal G and ground.

瀚慖f greater than 1 ohm, test the ground circuit for an open/high resistance.

7. Connect the harness connector at the ALC compressor.

8. Connect a 40-A fused jumper wire between the relay connector B+ circuit terminal 30 and the relay connector control circuit terminal 87.

Verify the ALC compressor is activated.

瀚慖f the ALC compressor does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the

ALC compressor.

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

10. Command the ALC compressor relay 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 electronic suspension