Autel Autolink AL301 [7/109] Obd ii definitions

For specific information on getting your vehicle’s OBD monitor

system ready, please consult your vehicle owner’s manual.

2.6 OBD II Definitions

Power-train Control Module (PCM) -- OBD II terminology for the

on-board computer that controls engine and drive train.

Malfunction Indicator Light (MIL) -- Malfunction Indicator Light

(Service Engine Soon, Check Engine) is a term used for the light 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 light, it indicates that a problem has

been detected and the vehicle should be serviced as soon as possible.

Under certain conditions, the dashboard light will blink or flash. This

indicates a severe problem and flashing is intended to discourage

vehicle operation. The vehicle onboard diagnostic system can not turn

the MIL off until 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.

OBD II Drive Cycle -- A specific mode of vehicle operation that

provides conditions 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

onboard 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 through 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