Malfunction Indicator Light (MIL)
--Malfunction Indicator Lig ht (Service
Engine Soon, Check Engine) is a term used for the lig ht on the instrument
panel. It is to alert the driver and/or the repair technician that there is a
problem with one or more of vehicle's systems and may cause emissions
to exceed federal standards. If the MIL illuminates with a steady lig ht, it
indicates that a problem has been detected and the vehicle should be
serviced as soon as possible. Under certain conditions, the dashboard
lig ht will blink or flash. This indicates a severe problem and flashing is
intended to discourage vehicle operation. The vehicle on-board diagnostic
system can not turn the MIL off until the necessary repairs are completed
or the condition no longer exists.
DTC
--Diagnostic Trouble Codes (DTC) that identify which section of the
emission control system has malfunctioned.
Enabling criteria
--Also termed Enabling Conditions. They are the vehicle-
specific events or conditions that must occur within the engine before the
various monitors will set, or run. Some monitors require the vehicle to follow
a prescribed "drive cycle" routine as part of the enabling criteria. Drive
cycles vary among vehicles and for each monitor in any particular vehicle.
OBDII Drive Cycle
--A specific mode of vehicle operation that provides
condition required to set all the readiness monitors applicable to the vehicle
to the "ready" condition. The purpose of completing an OBD II drive cycle
is to force the vehicle to run its on-board diagnostics. Some form of a
drive cycle needs to be performed after DTCs have been erased from
the PCM's memory or after the battery has been disconnected. Running
throug h a vehicle's complete drive cycle will "set" the readiness monitors
so that future faults can be detected. Drive cycles vary depending on the
vehicle and the monitor that needs to be reset. For vehicle specific drive
cycle, consult the vehicle's Owner's Manual.
