2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 2205
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, P0481, or P0482 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 Ckt Open, Short Gnd, and Short Volts Test Status
* FC Relay 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, open the hood to disable the Auto-Stop function.
2. Ignition ON, verify the scan tool hood position parameter displays Open.
瀚慖f the hood position does not display Open, refer to DTC P254F (See: P Code Charts/P254F).
3. Ignition OFF, disconnect all 5 cooling fan relays.
4. Ignition ON, verify that a test lamp illuminates between ground and the ignition circuit terminal of each relay listed below:
* FAN LO Relay terminal 85
* FAN MID 1 Relay terminal 85
* FAN CNTRL Relay terminal 86
* FAN MID 2 Relay terminal 86
* FAN HI Relay terminal 86
瀚慖f the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and
the ignition circuit fuse is open, test all the components connected to the ignition voltage circuit and replace as necessary.
5. 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 MID 1 Relay terminal 86
* FAN CNTRL Relay terminal 85
* FAN MID 2 Relay terminal 85
* FAN HI Relay terminal 85
The DMM should display OL.
瀚慖f less than the specified range, test the appropriate relay coil control circuit for a short to ground. If the circuit tests normal, replace the
K20 ECM.
6. Command the appropriate cooling fan relay ON and OFF with a scan tool. The DMM should transition from OL when commanded OFF to
less than 1 V when commanded ON.
瀚慖f the circuit voltage does not correspond to the specified values, test the control circuit for an open/high resistance or for a short to
voltage. If the circuit tests normal, replace the K20 ECM.
7. If all circuits test normal, test or replace the appropriate KR20 relay.
