the next time the engine is started. A driving cycle consists of a cold
engine startup followed by mixed city/highway driving. No additional
vehicle service is required.
If the
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
indicator on can result in increased emissions, lower fuel
economy, reduced engine and transmission smoothness, and lead to more
costly repairs.
Readiness for Inspection/Maintenance (I/M) testing
Some state/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. Your vehicle may not pass the I/M
test if the
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 considered not ready for I/M testing.
If the
indicator is on or the bulb does not work, the vehicle may
need to be serviced. Refer to the On board diagnostics (OBD-II)
description in this chapter.
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
indicator blinks
eight times, it means that the vehicle is not ready for I/M testing; if
the
indicator stays on solid, it means that the vehicle is ready for
I/M testing.
The OBD-II system is designed to check the emission control system
during normal driving. A complete check may take several days. If the
vehicle is not ready for I/M testing, the following driving cycle consisting
of mixed city and highway driving may be performed:
15 minutes of steady driving on an expressway/highway followed by 20
minutes of stop-and-go driving with at least four 30 second idle periods.
2007 Navigator(nav)
Owners Guide (post-2002-fmt)
USA(fus)
Maintenance and Specifications
291
