Equus 3150 - ABS/SRS + OBD2 Diagnostic Tool - Manual (Page 58)

Using the Code Reader
I/M READINESS TESTING
56 OBD2
„ If the erase was not successful, an
advisory message shows on the
LCD display. Verify that the Code
Reader is properly connected to the
vehicle’s DLC and that the ignition is
on, then repeat steps 2 and 3, above.
Erasing DTCs does not fix the problem(s) that caused the code(s)
to be set. If proper repairs to correct the problem(s) that caused
the code(s) to be set are not made, the code(s) will appear again
(and the check engine light will illuminate) as soon as the vehicle
is driven long enough for its Monitors to complete their testing.
I/M READINESS TESTING
I/M is an Inspection and Maintenance program legislated by the
Government to meet federal clean-air standards.
The program requires that a vehicle be taken periodically to an
Emissions Station for an "Emissions Test" or "Smog Check,” where the
emissions-related components and systems are inspected and tested
for proper operation. Emissions Tests are generally performed once a
year, or once every two years.
On OBD2 systems, the I/M program is enhanced by requiring vehicles
to meet stricter test standards. One of the tests instituted by the Federal
Government is called I/M 240. On I/M 240, the vehicle under test is
driven under different speeds and load conditions on a dynamometer for
240 seconds, while the vehicle's emissions are measured.
Emissions tests vary depending on the geographic or regional
area in which the vehicle is registered. If the vehicle is
registered in a highly urbanized area, the I/M 240 is probably
the type of test required. If the vehicle is registered in a rural
area, the stricter “dynamometer type” test may not be required.
I/M Readiness Monitors
I/M Readiness shows whether the various emissions-related systems on
the vehicle are operating properly and are ready for Inspection and
Maintenance testing.
State and Federal Governments enacted Regulations, Procedures and
Emission Standards to ensure that all emissions-related components
and systems are continuously or periodically monitored, tested and
diagnosed whenever the vehicle is in operation. It also requires vehicle
manufacturers to automatically detect and report any problems or faults
that may increase the vehicle's emissions to an unacceptable level.
The vehicle's emissions control system consists of several components
or sub-systems (Oxygen Sensor, Catalytic Converter, EGR, Fuel
System, etc.) that aid in reducing vehicle emissions.
To have an efficient Vehicle Emission Control System, all the emissions-
related components and systems must work correctly whenever the
vehicle is in operation.