4
The following monitors are to be used for compression ignition engines
only:
1) EGR System
2) NMHC Catalyst
3) NOx Aftertreatment
4) Boost Pressure System
5) Exhaust Gas Sensor
6) PM Filter
OBD II Monitor Readiness Status
OBD II systems must indicate whether or not the vehicle’s PCM’s monitor
system has completed testing on each component. Components that have
been tested will be reported as “Ready”, or “Complete”, meaning they have
been tested by the OBD II system. The purpose of recording readiness
status is to allow inspectors to determine if the vehicle’s OBD II system has
tested all the components and/or systems.
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 or a disconnected battery, 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.