2010 Cadillac Truck Escalade AWD V8-6.2L Page 991
Conditions for Running the DTC
* Battery voltage is between 9-16 volts.
* The exhaust valve is commanded ON.
Conditions for Setting the DTC
* The exhaust solenoid control circuit is shorted to voltage, ground, or open when solenoid activation is commanded ON for 2.5 seconds.
* The exhaust solenoid supply voltage circuit is shorted to ground or open when solenoid activation is commanded ON for 5 seconds.
Action Taken When the DTC Sets
* The electronic suspension control system will be inoperative.
* The SERVICE SUSPENSION SYSTEM message will be displayed.
Conditions for Clearing the MIL/DTC
* DTC C0660 will change from a current DTC to a history DTC on the next ignition cycle.
* DTC C0660 will be cleared from history after 50 ignition cycles.
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 Exhaust Valve ON and OFF with the scan tool output control. The exhaust solenoid valve should turn ON and OFF
with each command.
Circuit/System Testing
1. Ignition OFF, disconnect the automatic level control (ALC) compressor exhaust solenoid.
2. Ignition ON, verify that a test lamp does not illuminate between the solenoid control circuit terminal C at the connector and ground.
锟斤拷If 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 B and ground.
锟斤拷If the test lamp does not illuminate, test the B+ circuits for a short to ground or an open/high resistance. If the circuit tests normal, test or
replace the ALC compressor.
4. Connect a test lamp between the B+ circuit terminal B and the control circuit terminal C.
5. With a scan tool, clear all ALC DTCs.
6. Command the exhaust solenoid ON and OFF. The test lamp should turn ON and OFF when changing between the commanded states.
锟斤拷If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ESCM.
