Malfunction Indicator Lamp (Mil)
WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2006 Mercury Mountaineer, 2006 Mercury Monterey, 2006 Mercury Montego, 2006 Mercury Milan, and 2006 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.
The MIL notifies the driver that the powertrain control module (PCM) has detected an on board diagnostic (OBD) emission-related component or system concern. When this occurs, an OBD diagnostic trouble code (DTC) sets.
- The MIL is located in the instrument cluster and is labeled CHECK ENGINE, SERVICE ENGINE SOON or the international standards organization (ISO) standard engine symbol.
- The MIL is illuminated during the instrument cluster prove out for approximately 4 seconds.
- For applications with a dedicated hard wire MIL circuit, the PCM illuminates the MIL until a profile ignition pickup (PIP) signal is detected. The Ranger uses a hard wire circuit.
- The MIL remains illuminated after instrument cluster prove out if:
- an emission-related concern and DTC exists.
- no PIP signal is detected (applications with a dedicated hard wire MIL circuit). The PIP signal is generated in the PCM using the crankshaft position (CKP) sensor. For these applications, the MIL can be helpful in diagnosing a no start.
- the PCM does not send a control message to the instrument cluster (applications with the MIL controlled through the communication link).
- the PCM is operating in the Hardware Limited Operation Strategy (HLOS).
- the MIL circuit is shorted to ground (applications with a dedicated hard wire MIL circuit).
- The MIL remains off during the instrument cluster prove out if:
- an indicator or instrument cluster concern is present.
- the MIL circuit is open (applications with a dedicated hard wire MIL circuit).
- To turn off the MIL after a repair, a reset command from the diagnostic tool must be sent, or 3 consecutive drive cycles must be completed without a concern.
- For all MIL concerns, go to SYMPTOM CHARTS .
- If the MIL flashes at a steady rate, a severe misfire condition may exist.
- If the MIL flashes erratically, the PCM can reset while cranking if the battery voltage is low.