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Home >> Chevrolet >> 2013 >> Tahoe LS, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 2022 (Engine Controls/Fuel - 5.3L, 6.0L, 6.2L - DTC P0442 To DTC P3449 And Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> Malfunction Indicator Lamp (MIL) Diagnosis >> Circuit/System Description

Circuit/System Description

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The malfunction indicator lamp (MIL) illuminates to inform the driver that an emission system fault has occurred and the engine control system requires service. Ignition voltage is supplied directly to the MIL. The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit when the emission system fault occurs. Under normal operating conditions, the MIL should be ON only when the ignition is ON and the engine is OFF.