
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended
to assure that emissions are at acceptable
levels for the life of the vehicle, helping to produce
a cleaner environment. The check engine light
comes on to indicate that there is a problem and
service is required. Malfunctions often will be
indicated by the system before any problem is
apparent. This may prevent more serious damage
to your vehicle. This system is also designed to
assist your service technician in correctly
diagnosing any malfunction.
Notice:If you keep driving your vehicle with
this light on, after awhile, your emission
controls may not work as well, your fuel
economy may not be as good, and your engine
may not run as smoothly. This could lead to
costly repairs that may not be covered by
your warranty.Notice:Modi cations made to the engine,
transmission, exhaust, intake, or fuel system
of your vehicle or the replacement of the
original tires with other than those of the same
Tire Performance Criteria (TPC) can affect
your vehicle’s emission controls and may
cause this light to come on. Modi cations to
these systems could lead to costly repairs
not covered by your warranty. This may also
result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 397.
This light should come on, as a check to show
you it is working, when the ignition is on and the
engine is not running. If the light does not
come on, have it repaired. This light will also
come on during a malfunction in one of two ways:
Light Flashing— A mis re condition has
been detected. A mis re increases vehicle
emissions and may damage the emission
control system on your vehicle. Diagnosis
and service may be required.
Light On Steady— An emission control
system malfunction has been detected on
your vehicle. Diagnosis and service may
be required.
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If the Light is Flashing
The following may prevent more serious damage
to your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the
amount of cargo being hauled as soon as
it is possible
If the light stops ashing and remains on steady,
see “If the Light Is On Steady” following.
If the light continues to ash, when it is safe to
do so, stop the vehicle. Find a safe place to
park your vehicle. Turn the key off, wait at least
10 seconds and restart the engine. If the light
remains on steady, see “If the Light Is On Steady”
following. If the light is still ashing, follow the
previous steps, and see your dealer for service
as soon as possible.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully
install the cap. SeeFilling the Tank on page 402.
The diagnostic system can determine if the
fuel cap has been left off or improperly installed.
A loose or missing fuel cap will allow fuel to
evaporate into the atmosphere. A few driving
trips with the cap properly installed should turn
the light off.
Did you just drive through a deep puddle of
water?
If so, your electrical system may be wet. The
condition will usually be corrected when the
electrical system dries out. A few driving trips
should turn the light off.
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Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
SeeGasoline Octane on page 399. Poor fuel
quality will cause your engine not to run as
efficiently as designed. You may notice this as
stalling after start-up, stalling when you put
the vehicle into gear, mis ring, hesitation on
acceleration, or stumbling on acceleration.
(These conditions may go away once the engine
is warmed up.) This will be detected by the
system and cause the light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at
least one full tank of the proper fuel to turn the
light off.
If none of the above steps have made the light
turn off, your dealer can check the vehicle.
Your dealer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that may have developed.Emissions Inspection and
Maintenance Programs
Some state/provincial and local governments have
or may begin programs to inspect the emission
control equipment on your vehicle. Failure to pass
this inspection could prevent you from getting a
vehicle registration.
Here are some things you need to know to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the
check engine light is on or not working properly.
Your vehicle will not pass this inspection if
the OBD (on-board diagnostic) system determines
that critical emission control systems have not
been completely diagnosed by the system.
The vehicle would be considered not ready for
inspection. This can happen if you have recently
replaced your battery or if your battery has
run down. The diagnostic system is designed
to evaluate critical emission control systems during
normal driving. This may take several days of
routine driving. If you have done this and
your vehicle still does not pass the inspection for
lack of OBD system readiness, your GM dealer
can prepare the vehicle for inspection.
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Tow/Haul Mode Light
This light is displayed
when the Tow/Haul
mode has been
activated.
For more information, seeTowing a Trailer on
page 380andTow/Haul Mode on page 135.
Fuel Gage
When the ignition
is on, the fuel gage
tells you about
how much fuel you
have left in your tank.The gage will rst indicate empty before you are
out of fuel, and you should get more fuel as
soon as possible.
Here are some situations you may experience with
your fuel gage. None of these indicate a problem
with the fuel gage.
At the gas station, the fuel pump shuts off
before the gage reads full.
It takes a little more or less fuel to ll up than
the fuel gage indicated. For example, the
gage may have indicated the tank was half full,
but it actually took a little more or less than
half the tank’s capacity to ll the tank.
The gage goes back to empty when you turn
off the ignition.
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Driver Information Center (DIC)
Your vehicle has a Driver Information Center (DIC).
The DIC displays information about your vehicle.
It also displays warning messages if a system
problem is detected. The DIC also allows some
features to be customized. SeeDIC Vehicle
Customization on page 257for more information.
All messages will appear in the DIC display located
in the center of the instrument panel cluster.
The DIC comes on when the ignition is on. After
a short delay, the DIC will display the information
that was last displayed before the engine was
turned off.
SeeDIC Operation and Displays on page 243and
DIC Vehicle Customization on page 257for the
displays available.
DIC Operation and Displays
The DIC has different displays which can be
accessed by pressing the DIC buttons located
on the instrument panel, next to the steering wheel.
The DIC displays trip, fuel, and vehicle system
information, and warning messages if a system
problem is detected. A digital speedometer
also appears at the bottom of the DIC display. The
digital speedometer can be enabled or disabled.
See “DISPLAY DIGITAL SPEED” underDIC
Vehicle Customization on page 257for more
information.
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DIC Buttons
The buttons are
the trip/fuel,
vehicle information,
customization,
and set/reset buttons.
The button functions
are detailed in the
following pages.
3(Trip/Fuel):Press this button to display
the odometer, trip odometer, fuel range, average
economy, fuel used, timer, and transmission
temperature.
T(Vehicle Information):Press this button to
display the oil life, units, tire pressure readings
for vehicles with a Tire Pressure Monitor (TPM)
system, Tire Pressure Monitor (TPM) system
programming for vehicles with a TPM system, and
remote keyless entry transmitter programming.
U(Customization):Press this button to
customize the feature settings on your vehicle.
SeeDIC Vehicle Customization on page 257
for more information.
V(Set/Reset):Press this button to set or reset
certain functions and to turn off or acknowledge
messages on the DIC.
Trip/Fuel Menu Items
3
(Trip/Fuel):Press this button to scroll
through the following menu items:
Odometer
Press the trip/fuel button until ODOMETER
displays. This display shows the distance the
vehicle has been driven in either miles (mi)
or kilometers (km).
To switch between English and metric
measurements, see “Units” later in this section.
Trip Odometer
Press the trip/fuel button until TRIP displays. This
display shows the current distance traveled in
either miles (mi) or kilometers (km) since the last
reset for the trip odometer.
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The trip odometer can be reset to zero by pressing
the set/reset button while the trip odometer is
displayed.
Fuel Range
Press the trip/fuel button until FUEL RANGE
displays. This display shows the approximate
number of remaining miles (mi) or kilometers (km)
the vehicle can be driven without refueling. The
display will show LOW if the fuel level is low.
The fuel range estimate is based on an average
of the vehicle’s fuel economy over recent
driving history and the amount of fuel remaining
in the fuel tank. This estimate will change if driving
conditions change. For example, if driving in
traffic and making frequent stops, this display
may read one number, but if the vehicle is driven
on a freeway, the number may change even
though the same amount of fuel is in the fuel tank.
This is because different driving conditions
produce different fuel economies. Generally,
freeway driving produces better fuel economy
than city driving. Fuel range cannot be reset.
Average Economy
Press the trip/fuel button until AVERAGE
ECONOMY displays. This display shows the
approximate average miles per gallon (mpg) or
liters per 100 kilometers (L/100 km). This number
is calculated based on the number of mpg
(L/100 km) recorded since the last time this menu
item was reset. To reset AVERAGE ECONOMY,
press and hold the set/reset button.
Fuel Used
Press the trip/fuel button until FUEL USED
displays. This display shows the number of
gallons (gal) or liters (L) of fuel used since the last
reset of this menu item. To reset the fuel used
information, press and hold the set/reset button
while FUEL USED is displayed.
245

Timer
Press the trip/fuel button until TIMER displays.
This display can be used as a timer.
To start the timer, press the set/reset button while
TIMER is displayed. The display will show the
amount of time that has passed since the timer was
last reset, not including time the ignition is off. Time
will continue to be counted as long as the ignition is
on, even if another display is being shown on the
DIC. The timer will record up to 99 hours,
59 minutes and 59 seconds (99:59:59) after which
the display will return to zero.
To stop the timer, press the set/reset button brie y
while TIMER is displayed.
To reset the timer to zero, press and hold the
set/reset button while TIMER is displayed.
Transmission Temperature
Press the trip/fuel button until TRANS TEMP
displays. This display shows the temperature of
the automatic transmission uid in either degrees
Fahrenheit (°F) or degrees Celsius (°C).
Blank Display
This display shows no information.
Vehicle Information Menu Items
T
(Vehicle Information):Press this button to
scroll through the following menu items:
Oil Life
Press the vehicle information button until OIL LIFE
REMAINING displays. This display shows an
estimate of the oil’s remaining useful life. If you see
99% OIL LIFE REMAINING on the display, that
means 99% of the current oil life remains. The
engine oil life system will alert you to change your
oil on a schedule consistent with your driving
conditions.
When the remaining oil life is low, the CHANGE
ENGINE OIL SOON message will appear on the
display. See “CHANGE ENGINE OIL SOON” under
DIC Warnings and Messages on page 248. You
should change your oil as soon as you can. See
Engine Oil on page 407. In addition to the engine oil
life system monitoring the oil life, additional
maintenance is recommended in the Maintenance
Schedule in this manual. SeeScheduled
Maintenance on page 523for more information.
246