Malfunction Indicator Light (MIL)

The MIL may also be referred to as the CHECK ENGINE light. MIL is located on the instrument cluster, just to the left of the tachometer. When ignition is first turned on, MIL should come on and remain on for 2 seconds to verify bulb and circuit operation, and then go off.

The Powertrain Control Module (PCM) monitors several different engine control system circuits. If malfunction occurs which affects vehicle emissions, a Diagnostic Trouble Code (DTC) will be stored in PCM and PCM enters limp-in mode. When DTC is stored in PCM, the PCM will turn on the MIL and MIL will remain on steady. If problem exists which does not affect vehicle emissions, a DTC will be stored in PCM but MIL will not be turned on.

If PCM detects active engine misfire severe enough to cause catalytic converter damage, MIL will flash to warn the driver of possible damage and DTC will be stored.

The PCM will turn off MIL when malfunction is not detected during 3 consecutive trips on all applications except an engine misfire or fuel system monitor.

NOTE: For additional information on engine misfire and fuel system monitor, see ON-BOARD DIAGNOSTICS .

The PCM will turn off MIL when malfunction is not detected during 3 engine misfire or fuel system monitor tests. The PCM performs engine misfire or fuel system monitor tests when engine is operating within 375 RPM and within 10 percent of the load of operating condition at which first malfunction was detected.

NOTE: If MIL does not come on and remain on for 2 seconds and then go off when ignition is first turned on, check instrument cluster for diagnosis of MIL. See appropriate BODY CONTROL COMPUTER TESTS article in ACCESSORIES & EQUIPMENT.