LAUNCH
CReader 319 User’s
8
strategy.
Continuous Monitors
-- Some of the vehicle components or systems are
continuously tested by the vehicle’s OBD II system, while others are tested
only under specific vehicle operating conditions. The continuously monitored
components listed below are always ready:
1
）
Misfire 2
）
Fuel System
3
）
Comprehensive Components (CCM)
Once the vehicle is running, the OBD II system is continuously checking the
above components, monitoring key engine sensors, watching for engine
misfire, and monitoring fuel demands.
Non-Continuous Monitors
-- Unlike the continuous monitors, many
emissions and engine system components require the vehicle to be operated
under specific conditions before the monitor is ready. These monitors are
termed non-continuous monitors and are listed below:
1) EGR System
2) O2 Sensors
3) Catalyst
4) Evaporative System
5) O2 Sensor Heater
6) Secondary air Injection
7) Heated Catalyst
8) A/C system
2.5 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 powertrain 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 code reader or a disconnected battery, can result
in Readiness Monitors being set to “Not Ready”. Since the three continuous
