Yukon Denali 4WD V8-6.0L Hybrid (2011)
Malfunction Indicator Lamp: Testing and Inspection
Malfunction Indicator Lamp (MIL) Diagnosis
Diagnostic Instructions
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Perform the Diagnostic System Check - Vehicle See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle prior to using this diagnostic procedure.
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Review Strategy Based Diagnosis See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis for an
overview of the diagnostic approach.
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Diagnostic Procedure Instructions See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
Circuit/System Description
Ignition voltage is supplied to the malfunction indicator lamp (MIL). The engine control module (ECM) turns the MIL ON by grounding the MIL control
circuit.
Reference Information
Schematic Reference
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Instrument Cluster Schematics See: Diagrams/Electrical Diagrams/Instrument Panel, Gauges and Warning Indicators/System Diagram/Instrument
Cluster Schematics
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Engine Controls Schematics See: Diagrams/Electrical Diagrams/Wiring Schematic Index
Connector End View Reference
Component Connector End Views See: Diagrams/Connector Views/Connector End Views By Name
Electrical Information Reference
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Circuit Testing See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing
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Connector Repairs See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs
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Testing for Intermittent Conditions and Poor Connections See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs
Scan Tool Reference
Control Module References See: Testing and Inspection/Programming and Relearningfor scan tool information
Circuit/System Verification
1. Ignition ON, command the MIL ON and OFF with a scan tool. The MIL should turn ON and OFF.
2. Engine idling, command the MIL ON and OFF with a scan tool while observing the following control circuit status parameters:
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MIL Circuit Short to Gnd Test Status
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MIL Circuit Open Test Status
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MIL Circuit Short to Voltage Test Status
Each parameter should toggle between OK and Not Run or Not Run and OK.
Circuit/System Testing
1. Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description See: Hybrid Drive
Systems/Description and Operation/Hybrid Modes of Operation Description.
2. Ignition ON, verify the scan tool hood position parameter displays Open.
‹› If the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle See: Testing and Inspection/Diagnostic
Trouble Code Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
3. Ignition ON, verify that the instrument panel cluster (IPC) warning indicators are illuminated.
‹› If the IPC warning indicators are not illuminated, 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, replace the IPC.
4. Ignition OFF, disconnect harness connector X1 at the ECM.