Malibu L4-2.4L (2010)
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. For example, a failure condition exists if the ECM detects low voltage when the MIL is commanded OFF, or high voltage when the MIL is
commanded ON.
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)
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/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
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Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Connector
Repairs/Connector Repairs)
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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)
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Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for 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 as commanded.
2. Command the MIL ON and OFF with a scan tool while observing the following control circuit status parameters:
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MIL Ckt. Short Gnd Test Status
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MIL Ckt. Open Test Status
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MIL Ckt. Short Volts Test Status
Each parameter should change from OK and Not Run or from Not Run and OK.
3. Operate the vehicle within the Conditions for Running the DTC to verify that 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 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.
2. Ignition OFF, disconnect ECM X1 harness connector. Ignition ON, the MIL should not illuminate.
