HHR L4-2.4L (2010)
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
The ignition system uses individual ignition coil/module assemblies for each cylinder. The engine control module (ECM) controls the individual coils by
transmitting timing pulses on the ignition control (IC) circuit of each ignition coil/module to enable a spark event. Each ignition coil/module has the
following circuits:
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Ignition voltage
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Ground
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IC
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Low reference
Diagnostic Aids
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Depending on location in the spliced ignition voltage circuit, a slight resistance can cause a misfire or a crank/no start concern. A voltage drop test
on the circuit will pinpoint this condition.
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A slight to moderate resistance on any IC circuit can cause a misfire before DTC P0351-P0354 sets.
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Extended engine cranking time, may foul the spark plugs with excessive fuel.
Reference Information
Schematic Reference
Engine Controls Schematics (See: Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
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
Programming and Relearning (See: Testing and Inspection/Programming and Relearning) for scan tool information
Special Tools
J 26792 HEI Spark Tester
Circuit/System Verification
1. Verify that the engine is in good mechanical condition before continuing with this diagnostic.
2. Verify the following conditions:
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The ignition coil/modules are correctly connected
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The proper firing order
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The proper spark plug type
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The proper spark plug gap and torque
Refer to Ignition System Specifications (See: Specifications) and Spark Plug Inspection (See: Spark Plug/Testing and Inspection).
Circuit/System Testing
