The power train control module (PCM) sets a monitor to “Ready” or “Complete” after an appropriate
drive cycle has been performed. The drive cycle that enables a monitor and sets readiness codes to
“Ready” varies for each individual monitor. Once a monitor is set as “Ready” or “
Complete”
，
it will remain in this state. A number of factors, including erasing of diagnostic trouble
codes (DTCs) with a scan tool, can result in Readiness Monitors being set to “Not Ready”. Since the
three continuous monitors are constantly evaluating, they will be reported as “Ready” all of the time.
If testing of a particular supported non-continuous monitor has not been completed, the monitor
status will be reported as “Not Complete ” or ‘‘ Not Ready ”
In order for the OBD monitor system to become ready, the vehicle should be driven under a variety of
normal operating conditions. These operating conditions may include a mix of highway driving and
stop and go, city type driving, and at least one overnight
—
off period, For specific information on
getting your vehicle* s OBD monitor system ready, please consult your vehicle owner* s manual.
1.4 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 on board diagnostic system cannot 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.
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 on board diagnostics. Some form of a drive
cycle needs to be performed after DTCs have been erased from the PCM's memory. 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 the monitor that needs to be reset. For
vehicle specific drive cycle, consult the vehicle’s Owner’ s Manual.
Freeze Frame Data --When an emissions related fault occurs, the OBD II system not only sets a code
but also records a snapshot of the vehicle operating parameter to help in identifying the problem.
This set of values is referred to as Freeze Frame Data and may include t engine parameters such as
engine RPM, vehicle speed, air flow, engine load, fuel pressure, fuel trim value, engine coolant s,
ignition timing advance, or closed loop start.
1.5 Vehicle Coverage
The KONNWEI KW310 OBDII/EOBD Scanner is specially designed to work with all OBD II compliant
vehicles, including those equipped with the next-generation protocol ——Control Area Network (CAN).
It is required by EPA that all 1996 and newer vehicles (cars and light trucks) sold in the United States
must be OBD II compliant and this includes all Domestic, Asian and European vehicles.
