Malfunction Indicator Lamp: Description and Operation

1991 Jaguar XJ-6 L6-4.0LSECTION Description and Operation

PURPOSE AND LOCATION
The "CHECK ENGINE" light (located in the instrument panel) is part of the "on-board diagnostic" capabilities of the engine management system. It illuminates to warn the driver of an engine related problem. The driver should have the vehicle inspected as soon as possible by a qualified technician.

OPERATION
If no faults exist, the "CHECK ENGINE" light illuminates when the ignition is ON and goes out several seconds after the engine has been started.

If a serious fault in the fuel injection or ignition system is detected, the "CHECK ENGINE" light illuminates and stays on until the defect is fixed.

Until the defect is fixed, the light will stay illuminated after the engine is started and stay ON until the ignition is turned OFF. It will illuminate every time the ignition is ON or the engine is running until the defect is repaired and the fault code cleared.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.