2005 GMC SIERRA DENALI Owners Manual

{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
could drown. If it is only shallow water, it can
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over. Do not drive through rushing
water.
SeeDriving in Rain and on Wet Roads on page 4-28for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage. Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule
for additional information.
4-25

Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to be
impaired — by alcohol or drugs, with night vision
problems, or by fatigue.Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust your inside rearview mirror to reduce the
glare from headlamps behind you.
Since you cannot see as well, you may need to
slow down and keep more space between you
and other vehicles.
Slow down, especially on higher speed roads. Your
headlamps can light up only so much road ahead.
In remote areas, watch for animals.
If you are tired, pull off the road in a safe place
and rest.
4-26

No one can see as well at night as in the daytime. But
as we get older these differences increase. A
50-year-old driver may require at least twice as much
light to see the same thing at night as a 20-year-old.
What you do in the daytime can also affect your
night vision. For example, if you spend the day in bright
sunshine you are wise to wear sunglasses. Your
eyes will have less trouble adjusting to night. But if you
are driving, do not wear sunglasses at night. They
may cut down on glare from headlamps, but they also
make a lot of things invisible.
You can be temporarily blinded by approaching
headlamps. It can take a second or two, or even
several seconds, for your eyes to re-adjust to the dark.
When you are faced with severe glare, as from a driver
who does not lower the high beams, or a vehicle with
misaimed headlamps, slow down a little. Avoid staring
directly into the approaching headlamps.Keep your windshield and all the glass on your vehicle
clean — inside and out. Glare at night is made much
worse by dirt on the glass. Even the inside of the glass
can build up a lm caused by dust. Dirty glass makes
lights dazzle and ash more than clean glass would,
making the pupils of your eyes contract repeatedly.
Remember that your headlamps light up far less of a
roadway when you are in a turn or curve. Keep your eyes
moving; that way, it is easier to pick out dimly lighted
objects. Just as your headlamps should be checked
regularly for proper aim, so should your eyes be
examined regularly. Some drivers suffer from night
blindness — the inability to see in dim light — and are not
even aware of it.
4-27

Driving in Rain and on Wet Roads
Rain and wet roads can mean driving trouble. On a wet
road, you cannot stop, accelerate, or turn as well
because your tire-to-road traction is not as good as on
dry roads. And, if your tires do not have much tread
left, you will get even less traction. It is always wise to
go slower and be cautious if rain starts to fall while
you are driving. The surface may get wet suddenly when
your reexes are tuned for driving on dry pavement.The heavier the rain, the harder it is to see. Even if your
windshield wiper blades are in good shape, a heavy
rain can make it harder to see road signs and
traffic signals, pavement markings, the edge of the road,
and even people walking.
It is wise to keep your wiping equipment in good shape
and keep your windshield washer tank lled with
washer uid. Replace your windshield wiper inserts
when they show signs of streaking or missing areas on
the windshield, or when strips of rubber start to
separate from the inserts.
Driving too fast through large water puddles or even
going through some car washes can cause problems,
too. The water may affect your brakes. Try to avoid
puddles. But if you cannot, try to slow down before
you hit them.
4-28

{CAUTION:
Wet brakes can cause accidents. They will not
work as well in a quick stop and may cause
pulling to one side. You could lose control of
the vehicle.
After driving through a large puddle of water
or a car wash, apply your brake pedal lightly
until your brakes work normally.
Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen if the road is wet enough and
you are going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
Hydroplaning does not happen often. But it can if your
tires do not have much tread or if the pressure in
one or more is low. It can happen if a lot of water is
standing on the road. If you can see reections
from trees, telephone poles, or other vehicles, and
raindrops dimple the water’s surface, there could be
hydroplaning.Hydroplaning usually happens at higher speeds. There
just is not a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
Driving Through Deep Standing Water
Notice:If you drive too quickly through deep
puddles or standing water, water can come in
through your engine’s air intake and badly damage
your engine. Never drive through water that is
slightly lower than the underbody of your vehicle. If
you cannot avoid deep puddles or standing water,
drive through them very slowly.
4-29

Driving Through Flowing Water
{CAUTION:
Flowing or rushing water creates strong forces.
If you try to drive through owing water, as you
might at a low water crossing, your vehicle can
be carried away. As little as six inches of
owing water can carry away a smaller vehicle.
If this happens, you and other vehicle
occupants could drown. Do not ignore police
warning signs, and otherwise be very cautious
about trying to drive through owing water.
Some Other Rainy Weather Tips
Turn on your low-beam headlamps — not just your
parking lamps — to help make you more visible to
others.
Besides slowing down, allow some extra following
distance. And be especially careful when you
pass another vehicle. Allow yourself more clear
room ahead, and be prepared to have your
view restricted by road spray.
Have good tires with proper tread depth. SeeTires
on page 5-56.
4-30

City Driving
One of the biggest problems with city streets is the
amount of traffic on them. You will want to watch out for
what the other drivers are doing and pay attention to
traffic signals.Here are ways to increase your safety in city driving:
Know the best way to get to where you are
going. Get a city map and plan your trip into
an unknown part of the city just as you would for a
cross-country trip.
Try to use the freeways that rim and crisscross
most large cities. You will save time and energy.
SeeFreeway Driving on page 4-32.
Treat a green light as a warning signal. A traffic
light is there because the corner is busy enough
to need it. When a light turns green, and just before
you start to move, check both ways for vehicles
that have not cleared the intersection or may
be running the red light.
4-31

Freeway Driving
Mile for mile, freeways — also called thruways, parkways,
expressways, turnpikes, or superhighways — are the
safest of all roads. But they have their own special rules.
The most important advice on freeway driving is: Keep
up with traffic and keep to the right. Drive at the
same speed most of the other drivers are driving.
Too-fast or too-slow driving breaks a smooth traffic ow.
Treat the left lane on a freeway as a passing lane.At the entrance, there is usually a ramp that leads to the
freeway. If you have a clear view of the freeway as you
drive along the entrance ramp, you should begin to check
traffic. Try to determine where you expect to blend with
the ow. Try to merge into the gap at close to the
prevailing speed. Switch on your turn signal, check your
mirrors, and glance over your shoulder as often as
necessary. Try to blend smoothly with the traffic ow.
Once you are on the freeway, adjust your speed to the
posted limit or to the prevailing rate if it is slower.
Stay in the right lane unless you want to pass.
Before changing lanes, check your mirrors. Then use
your turn signal.
Just before you leave the lane, glance quickly over your
shoulder to make sure there is not another vehicle in
your blind spot.
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.
4-32