brakes GMC SIERRA DENALI 2003 Owners Manual

These are some examples of vehicle symbols you may find on your vehicle:
POSSIBLE /r
CAUTION
INJURY
PROTECT EYES BY
SHIELDING
CAUSTIC
ACID COULD BATTERY
CAUSE
BURNS
AVOID
SPARKS
OR
FLAMES
SPARK
OR
COULD FLAME
'\Ir8
EXPLODE
BAlTERY LATCH BOTH LAP AND
SHOULDER BELTS TO
PROTECT OCCUPANT
48: @
DO NOT TWIST SAFm
BELT WHEN AlTACHING
FASTEN SEAT
BELTS
MOVE SEAT FULLY
\v!
REARWARD* /g
SECURE
CHILD SEAT
PULL BELT
COMPLETELY
THEN SECURE CHILD
SEAT
DO NOT INSTALL
A REAR-FACING
CHILD RESTRAINT
@o
POSITION 8
IN THIS SEATING
DO NOT INSTALL
A
CHILD RESTRAINT p?
FORWARD-FACING IN THIS SEATING POSITION
8
DOOR LOCK
UNLOCK SGHTING
- MASTER SWITCH B- / ,
SIGNALS @e
TURN
PARKING
PC
LAMPS
RUNNING
*:{io
DAYTIME LAMPS
LAMPS
#O
ENGINE
COOLANT
cc.
TEMP
CHARGING BAlTERY
SYSTEM
COOLANT
ENGINE OIL PRESSURE
W&
ANTI-LOCK (@)
BRAKES
FE E]
ACCESS
COOLANT
m-1
ENGINE FAN
OWNERS MANUAL
SERVICE
MANUAL
V

DRIVE (D) can be used when towing a trailer, carrying a
heavy load, driving on steep hills or for off-road
driving. You may want to shift the transmission to
THIRD
(3) or, if necessary, a lower gear selection if the
transmission shifts too often.
THIRD
(3): This position is also used for normal driving,
however it offers more power and lower fuel economy
than DRIVE (D).
SECOND
(2): This position gives you more power but
lower fuel economy. You can use SECOND
(2) on
hills. It can help control your speed as you go down
steep mountain roads, but then you would also want to
use your brakes occasionally.
If you manually select SECOND
(2), the transmission
will drive in second gear. You may use this feature
for reducing the speed of the rear wheels when you are
trying to start your vehicle from a stop on slippery
road surfaces. FIRST
(1): This position
gives you even more power
(but lower fuel economy) than SECOND
(2). You
can use it on very steep hills, or in deep snow or mud.
If the shift lever is put in FIRST (1) while the vehicle
is moving forward, the transmission won’t shift into first
gear until the vehicle is going slowly enough.
Notice: If your rear wheels won’t turn, don’t try to
drive. This might happen
if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don’t hold your
vehicle there with only the accelerator pedal.
This could overheat and damage the transmission.
Use your brakes or shift into PARK (P) to hold
your vehicle in position on a hill.
On cold days, approximately
32°F (OOC) or colder, your
transmission is designed to shift differently until the
engine reaches normal operating temperature. This is
intended to improve heater performance.
2-20

Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking
brake pedal with your left foot.
A chime will activate and the warning light will flash
when the parking brake is applied and the vehicle
is moving at least
3 mph (5 km/h) for at least three
seconds.
If the ignition is on when the parking brake is released,
the brake system warning light will go
off.
Notice: Driving with the parking brake on can
cause your rear brakes
to overheat. You may have
to replace them, and you could also damage
other parts
of your vehicle.
If you are towing a trailer and are parking on any hill,
see
Towing a Trailer on page 4-51.
To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge
of the lever, located
above the parking brake pedal, with the parking
brake symbol, to release the parking brake.
2-22

Torque Lock
If you are parking on a hill and you don’t shift your
transmission into PARK
(P) properly, the weight of the
vehicle may put too much force on the parking pawl
in the transmission. You may find it difficult to pull the
shift lever out of PARK
(P). This is called ”torque
lock.” To prevent torque lock, set the parking brake and
then shift into PARK (P) properly before you leave
the driver’s seat.
To find out how, see Shifting lnto
Park
(P) on page 2-23.
When you are ready to drive, move the shift lever out of
PARK
(P) before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some of the
pressure from the parking pawl in the transmission,
so
you can pull the shift lever out of PARK (P).
Shifting Out of Park (P)
Your vehicle has an automatic transmission shift lock
control system. You have to fully apply your regular
brakes before you can shift from PARK (P) when the
ignition
is in RUN. See Automatic Transmission
Operation on page
2- 18.
If you cannot shift out of PARK (P), ease pressure on
the shift lever and push the shift lever all the way up into
PARK
(P) as you maintain brake application. Then,
move the shift lever into the gear you want.
If you ever hold the brake pedal down but still can’t shift
out of PARK (P), try this:
1. Turn the key to LOCK.
2. Apply and hold the brake until the end of Step 4.
3. Shift the vehicle to NEUTRAL (N).
4. Start the vehicle and then shift to the drive gear
5. Have the system fixed as soon as you can.
you want.
2-25

Cruise Control
0 : off
I : On
t : Resume/Accelerate
R: Set With cruise control,
you can maintain
a speed of about
25 mph (40 km/h) or more without keeping your foot
on the accelerator.
This can really help on long trips. Cruise control does
not work at speeds below about
25 mph (40 km/h).
If you apply your brakes, or press the clutch pedal (if
equipped), the cruise control will disengage.
Cruise control can be dangerous where
you can’t drive safely at a steady speed.
So, don’t use your cruise control on
winding roads or in heavy traffic.
Cruise control can be dangerous on
slippery roads. On such roads, fast
changes
in tire traction can cause
needless wheel spinning, and you could
lose control. Don’t use cruise control on
slippery roads.
3-8

Your brake system may not be working
properly
if the brake system warning light is
on. Driving with the brake system warning light
on can lead to an accident.
If the light is still
on after you’ve pulled
off the road and stopped
carefully, have the vehicle towed for service.
~
Anti-Lock Brake System Warning
Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on for
several seconds. That’s
normal.
, I
If the light doesn’t come on then, have it fixed so it will
be ready to warn you
if there is a problem.
If the light stays on, or comes on when you’re driving,
your vehicle needs service.
You will also hear a
chime sound when the light
is on steady. If the regular
brake system warning light isn’t on, you still have
brakes, but you don’t have anti-lock brakes. If the
regular brake system warning light is also on you don’t
have anti-lock brakes and there’s a problem with
your regular brakes.
In addition to both lights, you will
also hear a chime sound on the first occurrence of
a problem and each time the car is shut
off and then
restarted. See
Brake System Warning Light on
page 3-34 earlier in this section.
3-35

SERVICE AIRBAG
If there is a problem with the air bag system, this
message will be displayed on the
DIC. Have a qualified
technician inspect the system for problems. Pressing
the select button will acknowledge this message
and clear it from the
DIC display.
SERVICE BRAKE SYSTEM
If there is a problem with the brake system, this
message will be displayed on the
DIC. If this message
appears, stop as soon as possible and turn
off the
vehicle. Restart the vehicle and check for the message
on the
DIC display. If the message is still displayed,
or appears again when you begin driving, the brake
system needs service.
SERVICE BRAKE BOOSTER
If your vehicle has vaccum assist power brakes, this
message will be displayed on the
DIC when there is a
problem with the Supplemental Brake Assist system.
If the message is displayed immediately after starting
the vehicle or the message appears while driving,
your Supplemental Brake Assist system needs service.
See
Brake System Warning Light on page 3-34.
Your brake system may not be working
properly if the SERVICE BRAKE BOOSTER
message is displayed.
If the brake system warning light is also on,
you should have the vehicle towed for service. See “Brake System Warning Light”
in the
Index.
If the brake system warning light
isn’t on, you
still have brakes, but the supplemental brake
assist system may not operate properly.
In the
event of a vacuum
loss, you may not have
vacuum power assist for braking. The brake pedal will
be harder to push and it will take
longer to stop.
If you continue to drive with
this message displayed it can lead to a crash.
Have the brake system serviced as soon as
possible.
3-55

REDUCED BRAKE POWER
If your vehicle has vacuum assist power brakes, this
message will be displayed and you may notice that the
brake pedal is harder to push and it will take longer
to stop. You may also hear a motor running and feel a
slight vibration in the brake pedal or steering wheel
when you apply or release the brake pedal even
if your
foot is not on the brake pedal. This indicates that the
Supplemental Brake Assist system is working to
maintain braking power.
If you are braking lightly, you
may not notice any difference in the operation
of
your brakes.
This message may also be displayed for brief periods
if
you are driving at higher elevations and are pumping
your brakes or braking hard. The message may
clear after you’ve lifted your foot from the accelerator
pedal an allowed the vehicle to coast
in gear or after you
have driven down to a lower elevation. This is a
normal operation of your brake system and does not
require that the brake system be serviced. However,
if
the message does not clear, your brake system
needs service. While the message is displayed you will
notice that the brake pedal is harder to push and
it
will take longer to stop. See Brake System Warning
Light
on page 3-34.
Your brake system may not be working
properly if the REDUCED BRAKE POWER
message is displayed. If this message comes
on and stays on while driving, pull
off the road
and stop carefully. The brake pedal will be
harder to push and
it will take longer to stop.
If the message is no longer displayed after you
have pulled
off the road and stopped, you can
continue driving.
However, if the message is still displayed, or if
it comes on again when you are driving, there
is a problem with your brake system. If you
continue to drive with this message displayed
it can lead to an accident. You should have the
vehicle towed for service. Also, see Brake
System Warning Light in the Index.
3-57

There’s something else about drinking and driving that
many people don’t know. Medical research shows
that alcohol in a person’s system can make crash
injuries worse, especially injuries to the brain, spinal
cord or heart. This means that when anyone who
has been drinking
- driver or passenger - is in a
crash, that person’s chance
of being killed or
permanently disabled is higher than
if the person had
not been drinking.
Drinmnn,,d and then driving
is verb ..angerous.
Your reflexes, perceptions, attentiveness and
judgement can be affected by even a small amount of alcohol. You can have a serious-or
even fatal-collision if you drive after drinking.
Please don’t drink and drive or ride with a
driver who has been drinking. Ride home
in a
~ cab; or if you’re with a group, designate a
i driver who will not drink.
Control of a Vehicle
You have three systems that make your vehicle go where
you want it to go. They are the brakes, the steering and
the accelerator.
All three systems have to do their work at
the places where the tires meet the road.
Sometimes, as when you’re driving on snow or ice, it’s
easy to ask more
of those control systems than the
tires and road can provide. That means you can lose
control
of your vehicle.
4-5

‘\, Braking
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake pedal.
That’s
perception time. Then you have to bring up your
foot and do it. That’s
reaction time.
Average reaction time is about 3/4 of a second. But
that’s only an average. It might be less with one driver
and as long as two or three seconds or more with
another. Age, physical condition, alertness, coordination
and eyesight all play a part. So do alcohol, drugs and
frustration. But even in
3/4 of a second, a vehicle moving
at
60 mph (I00 km/h) travels 66 feet (20 m). That
could be a lot of distance in an emergency,
so keeping
enough space between your vehicle and others is
important.
And, of course, actual stopping distances vary greatly
with the surface of the road (whether it’s pavement
or gravel); the condition of the road (wet, dry, icy); tire
tread; the condition of your brakes; the weight of
the vehicle and the amount of brake force applied. Avoid needless
heavy braking. Some people drive in
spurts
- heavy acceleration followed by heavy
braking
- rather than keeping pace with traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster
if you do a lot of heavy braking. If you keep pace
with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking.
That means better braking and longer brake life.
If your engine ever stops while you’re driving, brake
normally but don’t pump your brakes. If you do,
the pedal may get harder
to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and
the brake pedal will be harder to push.
4-6