Page 491 of 599

ONBOARD DIAGNOSTIC SYSTEM (OBD II)
Your vehicle is equipped with a sophisticated onboard
diagnostic system called OBD II. This system monitors
the performance of the emissions, engine, and automatic
transmission control systems. When these systems are
operating properly, your vehicle will provide excellent
performance and fuel economy, as well as engine emis-
sions well within current government regulations.
If any of these systems require service, the OBD II system
will turn on the “Malfunction Indicator Light (MIL).” It
will also store diagnostic codes and other information to
assist your service technician in making repairs. Al-
though your vehicle will usually be drivable and not
need towing, see your authorized dealer for service as
soon as possible.
CAUTION!
•Prolonged driving with the MIL on could cause
further damage to the emission control system. It
could also affect fuel economy and driveability.
The vehicle must be serviced before any emissions
tests can be performed.
• If the MIL is flashing, while the engine is running,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines
that the fuel filler cap is loose, improperly
installed, or damaged, a loose gascap indicator
will display in the EVIC/DID telltale display
area. Refer to “Electronic Vehicle Information Center
7
MAINTAINING YOUR VEHICLE 489
Page 492 of 599

(EVIC)” or “Driver Information Display (DID)” in “Un-
derstanding Your Instrument Panel” for further informa-
tion. Tighten the fuel filler cap properly and press the
SELECT button to turn off the message. If the problem
continues, the message will appear the next time the
vehicle is started.
A loose, improperly installed, or damaged fuel filler cap
may also turn on the Malfunction Indicator Light (MIL).
EMISSIONS INSPECTION AND MAINTENANCE
PROGRAMS
In some localities, it may be a legal requirement to pass
an inspection of your vehicle’s emissions control system.
Failure to pass could prevent vehicle registration.For states that require an Inspection and Mainte-
nance (I/M), this check verifies the “Malfunction
Indicator Light (MIL)” is functioning and is not
on when the engine is running, and that the OBD II
system is ready for testing. Normally, the OBD II system will be ready. The OBD II
system may
notbe ready if your vehicle was recently
serviced, recently had a dead battery or a battery replace-
ment. If the OBD II system should be determined not
ready for the I/M test, your vehicle may fail the test.
Your vehicle has a simple ignition actuated test, which
you can use prior to going to the test station. To check if
your vehicle’s OBD II system is ready, you must do the
following:
1. Cycle the ignition switch to the ON position, but do not crank or start the engine.
NOTE: If you crank or start the engine, you will have to
start this test over.
2. As soon as you cycle the ignition switch to the ON position, you will see the Malfunction Indicator Light
(MIL) symbol come on as part of a normal bulb check.
490 MAINTAINING YOUR VEHICLE
Page 528 of 599

Fluid Level Check
Check the fluid level when the engine is fully warmed up
and the transmission fluid is at normal operating tem-
perature. Driving with an improper fluid level will
greatly reduce the life of the transmission and of the
fluid. Check the fluid level whenever the vehicle is
serviced.
Fluid Level Check — Procedure
It is best to check the fluid level when the transmission is
at normal operating temperature (170-180°F / 77-82°C for
66RFE transmission, or 158–176°F / 70–80°C for AS66RC
transmission). This normally occurs after at least 15 miles
(25 km) of driving. At normal operating temperature the
fluid cannot be held comfortably between the fingertips.
You can read the transmission sump temperature in theEVIC/DID display (refer to “Electronic Vehicle Informa-
tion Center (EVIC)/Driver Information Display (DID)” in
“Understanding Your Instrument Panel” for further in-
formation).
Use the following procedure to check the transmission
fluid level properly:
1. Monitor the transmission temperature using the
EVIC/DID display, and operate the vehicle as re-
quired to reach the normal operating temperature. If
the transmission is not functioning properly, or the
vehicle cannot be driven, see the NOTE and CAU-
TION below about checking the fluid level at colder
temperatures.
2. Park the vehicle on level ground.
3. Run the engine at normal idle speed for at least 60 seconds, and leave the engine running for the rest
of this procedure.
526 MAINTAINING YOUR VEHICLE
Page 562 of 599

MAINTENANCE SCHEDULE
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that ser-
vice is required for your vehicle. Operating conditions
such as frequent short-trips, trailer tow, extremely hot or
cold ambient temperatures, and E85 fuel usage will
influence when the “Oil Change Required” message is
displayed. Severe Operating Conditions can cause the
change oil message to illuminate as early as 3,500 miles
(5,600 km) since last reset. Have your vehicle serviced as
soon as possible, within the next 500 miles (805 km).
Your authorized dealer will reset the oil change indicator
message after completing the scheduled oil change. If a
scheduled oil change is performed by someone other
than your authorized dealer, the message can be reset byreferring to the steps described under “Electronic Vehicle
Information Center (EVIC)/Driver Information Display
(DID)” in “Understanding Your Instrument Panel” for
further information.
NOTE:
•
Gasoline Engines
• Under no circumstances should oil change intervals
exceed 8,000 miles (13,000 km) or twelve months,
whichever comes first.
• Severe Duty
•
Change Engine Oil at 4000 miles (6,500 km) if the vehicle
is operated in a dusty and off road environment. This
type of vehicle use is considered Severe Duty
Once A Month Or Before A Long Trip:
• Check engine oil level
• Check windshield washer fluid level
560 MAINTENANCE SCHEDULES