Malfunction Indicator Lamp: Description and Operation

1993 Chevrolet Astro Van M V6-262 4.3L VIN ZSECTION Description and Operation
PURPOSE
The Malfunction Indicator Lamp (MIL), "Service Engine Soon" light has the following purposes:
- Inform the driver that a problem has occurred, and that the vehicle should be taken for service as soon as reasonably possible.
- Displays Diagnostic Trouble Codes (DTC) stored by the ECM helping the technician diagnose system faults.
- Indicates "Open Loop" or "Closed Loop" operation.

OPERATION
The MIL will come "ON" with the key "ON" and the engine not running. When the engine is started, the light will turn "OFF.". This is a bulb and system check. If the light remains "ON," the self-diagnostic system has detected a problem. If the problem goes away, the light will go out in most cases after 10 seconds, but a DTC will remain stored in the ECM.
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:

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