7
Continuous Monitors:
Once the engine is running, the on board OBDII system is continuously monitoring key
engine sensors for engine misfire, and fuel demand. The continuous monitors are:
Other systems are tested only under specific operating conditions.
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
5.
O2 sensor heater
2.
O2 Sensor
6.
Secondary air
3.
Catalyst
7.
Heated catalyst
4.
Evaporative system
8.
A/C system
Definitions
OBDII
:
On-Board Diagnostics Generation Two
DLC
:
Data Link Connector is the multi-pin connection used to interface the code reader with
the control modules of a vehicle.
MIL
:
Malfunction Indicator Lamp -
same as “Service Engine Soon” or “Check Engine”. If the
MIL illuminates with a steady light, it indicates that a problem has been detected. If the MIL is
flashing a severe problem has been detected and further operation of the vehicle is
discouraged.
PCM
:
Powertrain Control Module, the on-board computer that controls engine and drive
train.
TCM
:
Transmission Control Module, the on-board computer that controls the transmission.
DTC
:
Diagnostic Trouble Codes
Identify which section of the emission control system has
malfunctioned.
Enabling criteria
also termed Enabling Conditions, are vehicle-specific events or
conditions that must occur within the engine before the various monitors will set or run. Some
monitors require the vehicle to follow a prescribed drive cycle routine as part of the enabling
criteria. Drive cycles vary among vehicles and for each monitor in any particular vehicle.
1.
Misfire
2.
Fuel system
3.
Comprehensive Components (CCM)
