Malfunction Indicator Lamp (Service Engine Soon)

MALFUNCTION INDICATOR LAMP (MIL)
The Malfunction Indicator Lamp (MIL) is displayed as an engine icon (graphic) on the instrument panel.

As a functional test, the MIL illuminates at key-on before engine cranking. Whenever the Powertrain Control Module (PCM) sets a Diagnostic Trouble Code (DTC) that affects vehicle emissions, it illuminates the MIL. If a problem is detected, the PCM sends a message to the instrument cluster to illuminate the lamp. The PCM illuminates the MIL only for DTC's that affect vehicle emissions. There are some monitors that may take two consecutive trips, with a detected fault, before the MIL is illuminated. The MIL stays on continuously when the PCM has entered a Limp-In mode or identified a failed emission component. Refer to the Diagnostic Trouble Code charts for emission related codes.

Also, the MIL either flashes or illuminates continuously when the PCM detects active engine misfire. Refer to Misfire Monitoring.

Additionally, the PCM may reset (turn off) the MIL when one of the following occur:
- PCM does not detect the malfunction for 3 consecutive trips (except misfire and Fuel system Monitors).
- PCM does not detect a malfunction while performing three successive engine misfire or fuel system tests. The PCM performs these tests while the engine is operating within ± 375 RPM of and within 10% of the load of the operating condition at which the malfunction was first detected.

SERVICE REMINDER INDICATOR (SRI) LAMP
The Service Reminder Indicator (SRI) lamp is used with the 5.9L HDC V-8 gasoline powered engine only. The lamp is displayed on the instrument panel as the MAINT REQ'D lamp.

The SRI system is incorporated into the Powertrain Control Module (PCM). The PCM records the vehicles mileage and stores it into memory. At that time, the PCM checks for certain mileage trip points. When the current mileage matches one of the trip points, the SRI lamp is activated.

Certain parts are to be replaced, or certain maintenance must be performed at either an indicated mileage or when the SRI lamp remains on when the key is in the ON position. After performing the part replacement or required maintenance, the SRI lamp must be reset to turn the lamp OFF. Use the DRB scan tool to reset the SRI lamp.

Failure to perform the part replacement or required maintenance and only reset the SRI lamp may be a violation of federal law. Only after performing the part replacement or required maintenance, should the SRI lamp be reset.