2003 BUICK CENTURY light

Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add
only DEX-COOL
žextended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating or if you need to add coolant to
your radiator, see
Engine Overheating on page 5-26.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
žcoolant will:
·Give freezing protection down to-34ÉF (-37ÉC).
·Give boiling protection up to 265ÉF (129ÉC).
·Protect against rust and corrosion.
·Help keep the proper engine temperature.
·Let the warning lights and gages work as they
should.
Notice:When adding coolant, it is important that
you use only DEX-COOLž(silicate-free) coolant.
If coolant other than DEX-COOLžis added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner Ð at 30,000 miles
(50,000 km) or 24 months, whichever occurs ®rst.
Damage caused by the use of coolant other
than DEX-COOL
žis not covered by your new vehicle
warranty.
5-23

Radiator Pressure Cap
Notice:Your radiator cap is a pressure-type cap
and must be tightly installed to prevent coolant loss
and possible engine damage from overheating.
Be sure the arrows on the cap line up with the
over¯ow tube on the radiator ®ller neck.
The radiator pressure cap is located near the front of
the engine compartment on the passenger's side of the
vehicle. See
Engine Compartment Overview on
page 5-12for more information on location.
Engine Overheating
You will ®nd a coolant temperature gage and a hot
engine warning light on your instrument panel.
See
Engine Coolant Temperature Gage on page 3-30andEngine Coolant Temperature Warning Light on
page 3-29.
Overheated Engine Protection
Operating Mode
The emergency engine protection operating mode
allows your vehicle to be driven to a safe place in an
emergency situation. If an overheated engine condition
exists, this protection mode alternates ®ring groups
of cylinders to help prevent engine damage. In
this mode, you will notice a signi®cant loss in power and
engine performance. The engine coolant temperature
gage indicator will move to the red area, showing that an
overheated engine condition exists. Driving extended
miles (km) and/or towing a trailer in the overheated
protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. See ªEngine Oilº in the Index.
5-26

When your brake ¯uid falls to a low level, your brake
warning light will come on. SeeBrake System Warning
Light on page 3-27.
What to Add
When you do need brake ¯uid, use only DOT-3 brake
¯uid. Use new brake ¯uid from a sealed container
only. See
Part D: Recommended Fluids and Lubricants
on page 6-16.
Always clean the brake ¯uid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of ¯uid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brake ¯uid.
Notice:
·Using the wrong ¯uid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they'll have to be replaced.
Don't let someone put in the wrong kind of ¯uid.
·If you spill brake ¯uid on your vehicle's painted
surfaces, the paint ®nish can be damaged. Be
careful not to spill brake ¯uid on your vehicle. If
you do, wash it off immediately. See
ªAppearance Careº in the Index. United States
Canada
5-40

Brake Wear
Your vehicle has front disc brakes and rear drum
brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving (except when you are pushing on the
brake pedal ®rmly).
{CAUTION:
The brake wear warning sound means that
soon your brakes won't work well. That could
lead to an accident. When you hear the brake
wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.Some driving conditions or climates may cause a brake
squeal when the brakes are ®rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque speci®cations.
Your rear drum brakes don't have wear indicators, but if
you ever hear a rear brake rubbing noise, have the
rear brake linings inspected immediately. Also, the rear
brake drums should be removed and inspected each
time the tires are removed for rotation or changing.
When you have the front brake pads replaced have the
rear brakes inspected, too.
Brake linings should always be replaced as complete
axle sets.
See
Brake System Inspection on page 6-15.
Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in
pedal travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you apply the brakes, with or without the
vehicle moving, your brakes adjust for wear.
5-41

Jump Starting
If your battery has run down, you may want to use
another vehicle and some jumper cables to start your
vehicle. Be sure to follow the steps below to do it safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
·They contain acid that can burn you.
·They contain gas that can explode or
ignite.
·They contain enough electricity
to burn you.
If you don't follow these steps exactly, some
or all of these things can hurt you.
Notice:Ignoring these steps could result in costly
damage to your vehicle that wouldn't be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
won't work, and it could damage your vehicle.1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
Notice:If the other system isn't a 12-volt system
with a negative ground, both vehicles can be
damaged.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake ®rmly on both vehicles involved in
the jump start procedure. Put an automatic
transaxle in PARK (P)or a manual transmission in
NEUTRAL (N) before setting the parking brake.
Notice:If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the auxiliary power outlet. Turn off
the radio and all lamps that aren't needed. This will
avoid sparks and help save both batteries. And it
could save your radio!
5-43

{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
¯ashlight if you need more light.
Be sure the battery has enough water. You
don't need to add water to the ACDelco
ž
battery installed in your new vehicle. But if a
battery has ®ller caps, be sure the right
amount of ¯uid is there. If it is low, add water
to take care of that ®rst. If you don't, explosive
gas could be present.
Battery ¯uid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, ¯ush the place with
water and get medical help immediately.
{CAUTION:
Fans or other moving engine parts can injure
you badly. Keep your hands away from moving
parts once the engine is running.
5. Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a
shock. The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) will go to
positive (+) or to a remote positive (+) terminal if
the vehicle has one. Negative (-) will go to a heavy,
unpainted metal engine part or to a remote
negative (-) terminal if the vehicle has one.
Don't connect positive (+) to negative (-) or you'll
get a short that would damage the battery and
maybe other parts too. And don't connect the
negative (-) cable to the negative (-) terminal on
the dead battery because this can cause sparks.
5-45

Notice:Don't let anyone tell you that underin¯ation
or overin¯ation is all right. It's not. If your tires
don't have enough air (underin¯ation), you can get
the following:
·Too much ¯exing
·Too much heat
·Tire overloading
·Bad wear
·Bad handling
·Bad fuel economy
If your tires have too much air (overin¯ation), you
can get the following:
·Unusual wear
·Bad handling
·Rough ride
·Needless damage from road hazards
When to Check
Check your tires once a month or more.
Don't forget your compact spare tire. It should be at
60 psi (420 kPa).
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can't tell if your tires are properly in¯ated
simply by looking at them. Radial tires may look
properly in¯ated even when they're underin¯ated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Tire Pressure Monitor System
If your vehicle has the tire in¯ation monitor system, it
can alert you to a large change in the pressure of
one tire. The system ªlearnsº the pressure at each tire
throughout the operating speed range of your vehicle.
The system normally takes between 45 and 90 minutes
of driving to learn the tire pressures. This time may
be longer depending on your individual driving habits.
Learning need not be accumulated during a single
trip. Once learned, the system will remember the tire
pressures until the system is recalibrated.
After the system has learned tire pressures with properly
in¯ated tires, the LOW TIRE light will come on if the
pressure in one tire becomes 12 psi (83 kPa) lower than
the other three tires. The tire in¯ation monitor system
won't alert you if the pressure in more than one tire is low,
if the system is not properly calibrated, or if the vehicle is
moving faster than 70 mph (110 km/h).
5-58

The tire in¯ation monitor system detects differences in tire
rotation speeds that are caused by changes in tire
pressure. The system can alert you about a low tire ± but
it doesn't replace normal tire maintenance. See
Tires on
page 5-57.
When the LOW TIRE light comes on, you should stop
as soon as you can and check all your tires for damage.
(If a tire is ¯at, see
If a Tire Goes Flat on page 5-66.)
Also check the tire pressure in all four tires as soon as
you can. See
In¯ation -- Tire Pressure on page 5-57.
The LOW TIRE light will also be displayed (while
the ignition is on) until you reset (calibrate) the system.
Don't reset the tire in¯ation monitor system without
®rst correcting the cause of the problem and checking
and adjusting the pressure in all four tires. If you
reset the system when the tire pressures are incorrect,
the system will not work properly and may not alert
you when a tire is low.
Any time you adjust a tire's pressure, rotate your tires,
or have one or more tires repaired or replaced, you'll
need to reset (calibrate) the tire in¯ation monitor system.
You'll also need to reset the system whenever you
buy new tires and whenever the vehicle's battery has
been disconnected.To reset (calibrate) the system:
1. Turn the ignition to RUN.
2. Locate the red RESET button inside of your
instrument panel fuse block.
The fuse block is located under the cover labeled
FUSES, which is at the end of the instrument panel
on the passenger's side of the vehicle. The
RESET button is the ®rst button in the top row of
the fuse block.
3. Press and hold the RESET button for about ®ve
seconds.
The LOW TIRE light will come on and ¯ash three
times. Then it will go off. If the light doesn't go
off, see your dealer for service.
The system completes the calibration process during
driving.
The system normally takes 15 to 20 minutes of driving
in each of three speed ranges to ªlearnº tire pressures.
The speed ranges are 15 to 40 mph (25 to 65 km/h),
40 to 65 mph (65 to 105 km/h) and above 65 mph
(105 km/h). When learning is complete, the system will
alert you after two to eight minutes if a tire is 12 psi
(83 kPa) different from the other three tires. Detection
thresholds may be higher and detection times may
be longer on rough roads, curves and at high speeds.
The system is not capable of detection at speeds greater
than 70 mph (110 km/h).
5-59