2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 2198
* The scan tool cooling fan output control operates as follows:
- Fan Relay 1 operates both fans at a low speed
- Fan Relay 2 and 3 operates one fan at high speed
- Fan Relays 1, 2, and 3 operates both fans at high speed
Reference Information
Schematic Reference
Engine Cooling Schematics (See: Engine, Cooling and Exhaust/Cooling System/Diagrams)
Connector End View Reference
* Component Connector End Views (See: Diagrams/Connector Views)
* Powertrain Component Views (See: Locations/Component Locations/Powertrain Component Views)
* Electrical Center Identification Views (See: Maintenance/Fuses and Circuit Breakers/Fuse/Application and ID)
Description and Operation
Cooling Fan Description and Operation (Gas) (See: Engine, Cooling and Exhaust/Cooling System/Description and Operation/Cooling Fan
Description and Operation (Gas))
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)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)
Circuit/System Verification
1. Engine operating, observe the DTC information with a scan tool. DTC P0480 or P0481 should not be set.
2. Command the cooling fans ON and OFF at high speed while observing the scan tool circuit test status parameters listed below:
* FC Relay 1 Ckt Open, Short Gnd, and Short Volts Test Status
* FC Relay 2 and 3 Ckt Open, Short Gnd, and Short Volts Test Status
The parameters should display OK or Not Run in each of the commanded states.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the
conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, disconnect the 3 cooling fan relays listed below.
* FAN LO relay
* FAN CNTRL relay
* FAN HI relay
2. Ignition ON, verify that a test lamp illuminates between ground and the ignition circuit terminal 85 of each relay.
瀚慖f the test lamp does not illuminate, test the ignition circuit for an open/high resistance.
3. Set the DMM on the diode setting. Connect the black lead to ground. Connect the red lead of the DMM to a control circuit terminal listed
below:
* FAN LO Relay terminal 86
* FAN CNTRL Relay terminal 86
* FAN HI Relay terminal 86
The DMM should display OL.
