6 7
2.3 Location of the Data Link
Connector (DLC)
The DLC(Data Link Connector or Diagnostic
Link Connector) is the Standardized 16-cavity
connector where diagnostic scan tools
interface With the vehicle’s side for most
vehicles. If Data Link Connector is not
Located under dashboard, a label should be
there telling location. For Some Asian and
European vehicles, the DLC is located behind
the ashtray And the ashtray must be removed
to access the connector. If the DLC cannot
Be found, refer to the vehicle service manual
for the location.
2.4 OBDII Readiness Monitors
An important part of a vehicle’s OBDII
system is the Readiness Monitors, which
are indicators used to find out if all of
the emissions components have been
evaluated by the OBD II system。They are
running periodic tests on specific systems
and components to ensure that they are
performing within allowable limits.
Currently, there are eleven OBD II Readiness
Monitors (or I/M Monitors). Not all monitors
in any vehicle depends on the motor vehicle
manufacturer emissions control 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 read.
These monitors are termed non-continuous
monitors. For different ignition type engines
the available monitors are different too.
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 read.
These monitors are termed non-continuous
monitors. For different ignition type engines
the available monitors are different too.
The following monitors are to be used for
spark ignition (Petrol) engines only:
1) EGR System
2) 02 Sensors
3) Catalyst
4) Evaporative System
5) 02 Sensor Heater Q Secondary air
7) Heated Catalyst
The following monitors are to be used for
compression ignition (Diesel) engines only:
1) EGR System
2) NMHC Catalyst
3) NOX after treatment
4) Boost pressure system
5) Exhaust gas sensor
6) PM filter
2.5 OBDII Monitor Readiness Status
OBD n 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 OBDII 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,
continuous monitors ; can result in Readiness
Monitors being set to “Not Ready”. Since
the three 。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 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.
To Next Page
Loading...
