2003 PONTIAC GRAND PRIX engine

Warning Lights, Gages and
Indicators
This part describes the warning lights and gages
that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle’s functions.
As you will
see in the details on the next few pages, some
warning lights come
on briefly when you start the
engine just to let you know they’re working.
If you are
familiar with this section, you should not be alarmed
when this happens. Gages can indicate
when there may be or is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together to let you know when
there’s a problem with your vehicle.
When one
of the warning lights comes on and stays on
when you are driving, or when one
of the gages shows
there may be a problem, check the section that tells
you what to do about it. Please follow this manual’s
advice. Waiting to do repairs can be costly
- and even
dangerous.
So please get to know your warning lights
and gages. They’re a big help.
Your vehicle may also have a Driver Information
Center (DIC) that works along with the warning lights
and gages. See Driver Information Center (DIC)
on page 3-38.
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Your vehicle is equipped with this cluster or one very
similar to it. It includes indicator warning lights and
gages that are explained on the following pages.
Be sure to read about them.
Speedometer and Odometer
The speedometer lets you see your speed in both miles
per hour (mph) and kilometers per hour (km/h). The
odometer shows how far the vehicle has been driven in
either miles (used in the United States) or in kilometers
(used in Canada).
The vehicle has a tamper-resistant odometer.
If you see
silver lines between the numbers, you’ll know someone
has probably tampered with
it and the numbers may
not be correct.
You may wonder what happens
if the vehicle needs a
new odometer installed.
If the new one can be set to the
mileage total of the old odometer, then that will be
done.
If it can’t, then it will be set at zero and a label
must be put on the driver’s door to show the old mileage
reading when the new odometer was installed.
Trip Odometer
The trip odometer tells how far you have driven since
you last reset it.
To set it to zero, press the reset button
located to the right of the instrument panel cluster.
Tachometer
The tachometer displays the engine speed in thousands
of revolutions per minute (rpm).
Notice: Do not operate the engine with the
tachometer in the shaded warning area, or engine
damage may occur.
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Anti-Lock Brake System Warning Light
if your vehicle has the
optional anti-lock brake
system, this light will come
on when your engine is
started and may stay on
for several seconds.
That’s normal.
If the anti-lock brake system warning light stays on
longer than normal after you’ve started your engine, turn
the ignition
off. If the light comes on and stays on
while you’re driving, stop as soon as possible and turn
the ignition
off. Then start the engine again to reset
the system.
If the light still stays on, or comes on again
while you’re driving, your vehicle needs service.
If
the light is on and the regular brake system warning
light isn’t on, you still have brakes, but you don’t have
anti-lock brakes.
The anti-lock brake system warning light should come
on briefly when you turn the ignition key to
RUN. This is
normal.
If the light doesn’t come on then, have it
fixed
so it will be ready to warn you if there is a problem.
Traction Control System (TCS)
Warning Light
TCS
OFF
If your vehicle is
equipped with the 3800
supercharged V6 engine,
the traction control
system warning light
may come on for the
following reasons:
If you turn the system off by pressing the TCS
button located on the far right side of the trip
computer, the warning light will come on and stay
on. To turn the system back on, press the button
again. The warning light should go
off. See Traction
Control System (TCS) on page
4-10 for more
information.
@ If there’s a brake system problem that is specifically
related to traction control, the traction control
system will turn
off and the warning light will come
on. If your brakes begin to overheat, the traction
control system will turn
off and the warning light will
come on until your brakes cool down.
If the traction control system warning light comes on
and stays on for an extended period of time when the
system
is turned on, your vehicle needs service.
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Enhanced Traction System Warning
Light
TRAC
OFF
If your vehicle is equipped
with a
31 00 V6 or 3800 V6
engine and the optional
ABS brake system, the
Enhanced Traction System
warning light may come on
for the following reasons:
e
e
e
If you turn the system off by pressing the TRAC
button on the far right side of the Driver Information
Center or trip computer (if equipped), the warning
light will come on and stay on. To turn the system
back on, press the button again. The warning light
should go
off. See Enhanced Traction System (ETS)
on page 4-1 1 for more information.
If the Enhanced Traction System warning light
comes on and stays on for an extended period of
time while the system is turned on, your vehicle
needs service. Adjust your driving accordingly.
If the traction control system is affected by an
engine-related problem, the system will turn off and
the warning light will come on.
When this warning light is on, the system will not limit
wheel spin. Adjust your driving accordingly.
Low Traction Light
LOW
TRAC
If your vehicle has the
Enhanced Traction
System or the Traction
Control System, this light
will also come on while
the system is limiting
wheel spin.
You may feel or hear the system working, but this is
normal. Slippery road conditions may exist
if the
low traction light comes on,
so adjust your driving
accordingly. The light will stay on for a few seconds after
the Enhanced Traction System or the Traction Control
System stops limiting wheel spin. See Enhanced
Traction System
(ETS) on page 4-1 1 or Traction Control
System (TCS) on page
4- 10.
The low traction light also comes on briefly when you
turn the ignition key to RUN. If the light doesn’t come on
then, have it fixed so it will be there to tell you when
the Traction Control System or Enhanced Traction
System is active.
3-30

Engine Coolant Temperature
Warning Light
TEMP
This light tells goti ihai
the engine coolant has
overheated or the
radiator cooling fan is
not working.
If you have been operating the vehicle under normal
driving conditions, you should pull
of the road, stop the
vehicle and turn
off the engine as soon as possible.
See Engine Overheating on page
5-33.
Engine Coolant Temperature Gage
United States
19
Canada
Your vehicle has a gage that shows the engine coolant
temperature.
If the gage pointer moves into the
shaded area, the engine is too hot.
That reading means the same thing as the warning
light. It means that the engine coolant has overheated.
If you have been operating the vehicle under normal
conditions, you should pull
off the road, stop the vehicle,
and turn
off the engine as soon as possible.
See Engine Overheating
on page 5-33.
3-31

Malfunction indicator Lamp
Service Engine Soon Light in the
United States or Check Engine Light
in Canada
SERVICE
ENGINE SOON
United States
~~
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 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: Modifications made to the engine,
transaxle, 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.
Modifications 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.
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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 doesn’t come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
Light Flashing - A misfire condition has been
detected. A misfire increases vehicle emissions
and may damage the emission control system on
your vehicle. Dealer or qualified service center
diagnosis and service may be required.
0 Light On Steady - An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis
and service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:
0 Reducing vehicle speed.
0 Avoiding hard accelerations.
Avoiding steep uphill grades.
0 If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible. If
the light stops flashing and remains on steady,
see “If the Light
Is On Steady” following.
If the light continues to flash, 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 flashing, follow the
previous steps, and drive the vehicle
to your dealer or
qualified service center for service.
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. See Filling
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.
3-33

Are you low on fuel?
As your engine starts to run out of fuel, your engine
may not run as efficiently as designed since small
amounts of air are sucked into the fuel line causing
misfire. The system can detect this. Adding fuel should
correct this condition. Make sure to install the fuel
cap properly. See filling
Your Tank on page 5-7. It will
take a few driving trips to turn the light
off.
Have you recently changed brands of fuel?
If
so, be sure to fuel your vehicle with quality fuel. See
Gasoline Ocfane on page
5-5. 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, misfiring, 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,
have your dealer or qualified service center check
the vehicle. Your dealer has the proper test equipment
and diagnostic tools to fix 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, see your dealer or qualified service
center to prepare the vehicle for inspection.
3-34