4
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 code readers interface with the vehicle's on-board computer. The DLC is usually located 12 inches
from the center of the instrument panel (dash), under or around the driver
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.
2.4 OBD II Readiness Monitors
An important part of a vehiclewhich 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) defined by the U.S. Environmental Protection
Agency (EPA). Not all monitors are supported in every vehicles and the exact number of monitors in any vehicle depends
on the motor vehicle manufacturer
Continuous Monitors-- Some of the vehicle components or systems are
continuously tested by the vehicleonly 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:
EGR System
O2 Sensors
Catalyst
Evaporative System
O2 Sensor Heater
Secondary air Injection
Heated Catalyst
A/C system
2.5 OBD II Monitor Readiness Status
OBD II systems must indicate whether or not the vehiclesystem has completed testing on each component. Components
that have been tested will be reported as “Rady? or “Compete? meaning they have been tested by the OBD II system. The
purpose of recording readiness status is to allow inspectors to determine if the vehicleall the components and/or
systems.
The powertrain control module (PCM) sets a monitor to “eady?or “ompletecycle that enables a monitor and sets
readiness codes to “eady?varies for each individual monitor. Once a monitor is set as will remain in this state. A number