If the service engine soon indicator remains
on, have your vehicle serviced at the first
available opportunity. Although some
malfunctions detected by the OBD-II may not
have symptoms that are apparent, continued
driving with the service engine soon indicator
on can result in increased emissions, lower
fuel economy, reduced engine and
transmission smoothness and lead to more
costly repairs.
Readiness for Inspection and
Maintenance (I/M) Testing
Some state and provincial and local
governments may have
Inspection/Maintenance (I/M) programs to
inspect the emission control equipment on
your vehicle. Failure to pass this inspection
could prevent you from getting a vehicle
registration.
If the service engine soon indicator
is on or the bulb does not work,
your vehicle may need service.
See On-Board Diagnostics.Your vehicle may not pass the I/M test if the
service engine soon indicator is on or not
working properly (bulb is burned out), or if
the OBD-II system has determined that some
of the emission control systems have not
been properly checked. In this case, the
vehicle is not ready for I/M testing.
If the vehicle’s engine or transmission has
just been serviced, or the battery has
recently run down or been replaced, the
OBD-II system may indicate that the vehicle
is not ready for I/M testing. To determine if
the vehicle is ready for I/M testing, turn the
ignition key to the on position for 15 seconds
without cranking the engine. If the service
engine soon indicator blinks eight times, it
means that the vehicle is not ready for I/M
testing; if the service engine soon indicator
stays on solid, it means that your vehicle is
ready for I/M testing.
The OBD-II system checks the emission
control system during normal driving. A
complete check may take several days.
If the vehicle is not ready for I/M testing, you
can perform the following driving cycle
consisting of mixed city and highway driving:1. 15 minutes of steady driving on an
expressway or highway followed by 20
minutes of stop-and-go driving with at
least four 30-second idle periods.
2. Allow your vehicle to sit for at least eight
hours with the ignition off. Then, start the
vehicle and complete the above driving
cycle. The vehicle must warm up to its
normal operating temperature. Once
started, do not turn off the vehicle until
the above driving cycle is complete.
If the vehicle is still not ready for I/M testing,
you need to repeat the above driving cycle.
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Engine Emission Control
