Check Engine Light (MIL)

Category: automotive

A dashboard indicator signal from the car’s computer that a malfunction has been detected.

The Malfunction Indicator Lamp (MIL) alerts the driver to an issue with the emissions or powertrain system. It is triggered by the PCM when a sensor returns data outside of expected parameters, requiring an OBD-II scanner to read the specific diagnostic trouble code.

Common Examples

• The check engine light came on after a loose gas cap, which is a common and minor trigger for modern emissions systems.
• A flashing check engine light indicates a serious misfire that can cause immediate damage to your catalytic converter.