2003 GMC YUKON brakes

NEUTRAL (N):In this position, your engine doesn’t
connect with the wheels. To restart when you’re already
moving, use NEUTRAL (N) only. Also, use
NEUTRAL (N) when your two-wheel drive vehicle is
being towed.
{CAUTION:
Shifting into a drive gear while your engine is
“racing”(running at high speed) is dangerous.
Unless your foot isfirmly on the brake pedal,
your vehicle could move very rapidly. You
could lose control and hit people or objects.
Don’t shift into a drive gear while your engine
is racing.
Notice:Damage to your transmission caused by
shifting out of PARK (P) or NEUTRAL (N) with
the engine racing isn’t covered by your warranty.
DRIVE (D):This position is for normal driving. If
you need more power for passing, and you’re:
Going less than about 35 mph (56 km/h), push your
accelerator pedal about halfway down.
Going about 35 mph (56 km/h) or more, push the
accelerator all the way down.You’ll shift down to the next gear and have more power.
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 off and on.
If you manually select SECOND (2) in a light duty
automatic transmission, 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.
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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 intorst
gear until the vehicle is going slowly enough.
Notice:If your 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(0°C) or colder, your
transmission is designed to shift differently until the
engine reaches normal operating temperature. This is
intended to improve heater performance.Tow/Haul Mode
Your vehicle may be equipped with a tow/haul mode. If
so, the selector button is located on the end of the
column shift lever. You can use this feature to assist
when towing or hauling a heavy load. SeeTowing
a Trailer on page 4-61for more information.
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2003 - Yukon/Yukon XL

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 willash
when the parking brake is applied and the vehicle
is moving at least 3 mph (5 km/h) for at least
three seconds.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.
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,
seeTowing a Trailer on page 4-61.
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If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and the
parking brake isrmly set before you leave it. After you
move the shift lever into PARK (P), hold the regular
brake pedal down. Then, see if you can move the shift
lever away from PARK (P) withoutrst pulling it
toward you. If you can, it means that the shift lever
wasn’t fully locked into PARK (P).
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 maynd 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
nd out how, seeShifting Into Park (P) on page 2-35.
When you are ready to drive, move the shift lever out of
PARK (P)beforeyou 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. SeeAutomatic Transmission
Operation on page 2-22.
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
you want.
5. Have the systemxed as soon as you can.
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Cruise Control
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).
9:Off
R:On
S:Resume/Accelerate
T:Set
If you apply your brakes, the cruise control will
disengage.
{CAUTION:
•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.
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2003 - Yukon/Yukon XL

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 thefirst occurrence of
a problem and each time the vehicle is shut off and then
restarted. SeeBrake System Warning Light on
page 3-43.
Traction Off Light
If you have the Traction
Assist System, this light
should come on briefly
when you turn the ignition
to RUN.
If the light doesn’t come on then, the system may
require service; have itfixed so it will be there to warn
you if the system is turned off.If the light stays on, or comes on when you’re driving,
there may be a problem with your Traction Assist
System and your vehicle may need service. When this
light is on, the system will not limit wheel spin. Adjust
your driving accordingly.
The traction off light may come on for the following
reasons:
•If you turn the system off by pressing the TAS
on/off button located to the left of the steering wheel,
the light will come on and stay on. To turn the
system back on, press the button again; the light
should go off.
•If you move the shift lever to FIRST (1), the light
will come on and stay on to indicate that the
traction system is off. This is normal operation. To
turn the system back on, move the shift lever
back to a position other than FIRST (1); the light
should go off. SeeTraction Assist System (TAS) on
page 4-10.
•The light will come on and stay on if the TAS
automatic engagement feature has been turned off.
To turn the system on, press the TAS off/on
button; the light should go off. To turn the automatic
engagement feature back on, seeTraction Assist
System (TAS) on page 4-10.
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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.
SeeBrake System Warning Light on page 3-43.{CAUTION:
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.
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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. Also seeTraction Assist
System (TAS) on page 4-10.
Braking
Braking action involvesperception timeand
reaction time.
First, you have to decide to push on the brake pedal.
That’sperception time.Then you have to bring up your
foot and do it. That’sreaction time.
Averagereaction timeis 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 (100 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
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2003 - Yukon/Yukon XL