Malfunction Indicator Lamp
Service Engine Soon Light
in the United States or
Check Engine Light in Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition, and emission
control systems.
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 SERVICE ENGINE SOON or CHECK
ENGINE light comes on and a chime will sound 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 a while, 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. United States
Canada
3-29
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.
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 Your Tank on page 5-7. 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.
3-30
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-4. 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 SERVICE
ENGINE SOON or 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.
3-31
Tow/Haul Mode Light
This light should come on
when the tow/haul mode
has been selected.
For more information, see “Tow/Haul Mode” inTowing
a Trailer on page 4-35.
Check Gages Warning Light
The CHECK GAGES
light will come on brie y
when you are starting
the engine.
If the light comes on and stays on while you are driving,
check your coolant temperature and engine oil pressure
gages to see if they are in the warning zones.
Fuel Gage
The fuel gage tells you approximately how much fuel
you have remaining when the ignition is on.
When the gage rst indicates empty, you still have a
little fuel left, but you should get more fuel as soon
as possible.
United StatesCanada
3-34
Here are things some owners ask about. None of these
indicate a problem with your fuel gage:
At the gas station, the gas pump shuts off before
the gage reads full.
The fuel tank will take either a little more or a little
less fuel to ll up than the gage shows.
The gage moves a little when you turn a corner or
speed up.
The gage doesn’t go back to empty when you turn
off the ignition.
Low Fuel Warning Light
The LOW FUEL light
will come on brie y
when you are starting
the engine.
This light comes on when the fuel tank is low
on fuel. To turn it off, add fuel to the fuel tank.
SeeFuel on page 5-4.
Audio System(s)
Notice:Before adding any sound equipment to
your vehicle, like a tape player, CB radio, mobile
telephone, or two-way radio, make sure that it can
be added by checking with your dealer. Also,
check federal rules covering mobile radio and
telephone units. If sound equipment can be added,
it is very important to do it properly. Added
sound equipment may interfere with the operation
of your vehicle’s engine, radio, or other systems,
and even damage them. Your vehicle’s systems may
interfere with the operation of sound equipment
that has been added improperly.
Figure out which audio system is in your vehicle, nd
out what your audio system can do, and how to operate
all of its controls.
Your vehicle has a feature called Retained Accessory
Power (RAP). With RAP, the audio system can be
played even after the ignition is turned off. See
“Retained Accessory Power (RAP)” underIgnition
Positions on page 2-18.
3-35
Once you are moving on the freeway, make certain
you allow a reasonable following distance. Expect
to move slightly slower at night.
When you want to leave the freeway, move to the
proper lane well in advance. If you miss your exit,
do not, under any circumstances, stop and back up.
Drive on to the next exit.
The exit ramp can be curved, sometimes quite sharply.
The exit speed is usually posted.
Reduce your speed according to your speedometer,
not to your sense of motion. After driving for any
distance at higher speeds, you may tend to think you
are going slower than you actually are.
Before Leaving on a Long Trip
Make sure you are ready. Try to be well rested. If you
must start when you are not fresh — such as after
a day’s work — do not plan to make too many miles
that rst part of the journey. Wear comfortable clothing
and shoes you can easily drive in.Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it is ready to go. If it needs
service, have it done before starting out. Of course, you
will nd experienced and able service experts in GM
dealerships all across North America. They will be ready
and willing to help if you need it.
Here are some things you can check before a trip:
Windshield Washer Fluid:Is the reservoir full?
Are all windows clean inside and outside?
Wiper Blades:Are they in good shape?
Fuel, Engine Oil, Other Fluids:Have you checked
all levels?
Lamps:Are they all working? Are the lenses clean?
Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough for
long-distance driving? Are the tires all in ated
to the recommended pressure?
Weather Forecasts:What is the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
Maps:Do you have up-to-date maps?
4-20
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You can not see
it or smell it, so you might not know it is in
your vehicle. Clear away snow from around
the base of your vehicle, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.Run your engine only as long as you must. This
saves fuel. When you run the engine, make it go a
little faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get
and it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine off and close the window
almost all the way to preserve the heat. Start the
engine again and repeat this only when you feel
really uncomfortable from the cold. But do it as little
as possible. Preserve the fuel as long as you can.
To help keep warm, you can get out of the vehicle
and do some fairly vigorous exercises every half hour
or so until help comes.
4-27