User Manual
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Professional 909X User Manual
vehicles and for each monitor in any particular vehicle. Please refer to the
vehicle’s factory service manual for specic enabling procedures.
Trip - A Trip for a particular Monitor requires that the vehicle is being driven in
such a way that all the required “Enabling Criteria” for the Monitor to run and
complete its diagnostic testing are met. The “Trip Drive Cycle” for a particular
Monitor begins when the ignition key is turned “On.” It is successfully completed
when all the “Enabling Criteria” for the Monitor to run and complete its diagnostic
testing are met by the time the ignition key is turned “Off.” Since each of the
fifteen monitors is designed to run diagnostics and testing on a different part
of the engine or emissions system, the “Trip Drive Cycle” needed for each
individual Monitor to run and complete varies.
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 the monitor that needs to be reset. For
vehicle specic drive cycle, consult the service manual.
Note: Do not confuse a “Trip” Drive Cycle with an OBD II Drive Cycle. A
“Trip” Drive Cycle provides the “Enabling Criteria” for one specic Monitor to
run and complete its diagnostic testing. An OBD II Drive Cycle must meet the
“Enabling Criteria” for all Monitors on a particular vehicle to run and complete
their diagnostic testing.
Warm-up Cycle - Vehicle operation after an engine off period where engine
temperature rises at least 40°F (22°C) from its temperature before starting, and
reaches at least 160°F (70°C). The PCM uses warm-up cycles as a counter to
automatically erase a specic code and related data from its memory. When no
faults related to the original problem are detected within a specied number of
warm-up cycles, the code is erased automatically.
Fuel Trim (FT) - Feedback adjustments to the base fuel schedule. Short-term
fuel trim refers to dynamic or instantaneous adjustments. Long-term fuel trim
refers to much more gradual adjustments to the fuel calibration schedule than
short-term trim adjustments. These long-term adjustments compensate for
vehicle differences and gradual changes that occur over time.