Yukon Denali 4WD V8-6.0L Hybrid (2011)
Ignition Coil: Testing and Inspection
Electronic Ignition System 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
This ignition system uses individual ignition module/coil assemblies for each cylinder. The engine control module (ECM) controls the spark events by
transmitting the timing pulses on the ignition control (IC) circuits to the individual ignition module/coil assemblies in firing order sequence.
Reference Information
Schematic Reference
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
Special Tools
J 26792 Spark Plug Tester
Circuit/System Verification
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: Computers and Control
Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
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: Computers and Control
Systems/Testing and Inspection/Diagnostic Trouble Code Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
3. Ignition OFF for 1 minute, disconnect the harness connector at the ignition coil.
4. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohm between the ground circuit terminal B and ground.
‹› If greater than the specified range, repair the ground circuit for an open/high resistance.
5. Test for less than 5 ohm between the low reference circuit terminal C and ground.
