2007 GMC SIERRA Owner's Manual

{CAUTION:
Coasting downhill in NEUTRAL (N) or with
the ignition off is dangerous. The brakes
will have to do all the work of slowing
down. They could get so hot that they
would not work well. You would then have
poor braking or even none going down a
hill. You could crash. Always have the
engine running and your vehicle in gear
when you go downhill.
Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift to a lower gear when
you go down a steep or long hill.
Know how to go uphill. You may want to shift
down to a lower gear. The lower gears help
cool your engine and transmission, and you can
climb the hill better.
Stay in your own lane when driving on two-lane
roads in hills or mountains. Do not swing wide
or cut across the center of the road. Drive at
speeds that let you stay in your own lane.
As you go over the top of a hill, be alert. There
could be something in your lane, like a stalled
car or an accident.
You may see highway signs on mountains that
warn of special problems. Examples are long
grades, passing or no-passing zones, a falling
rocks area, or winding roads. Be alert to these
and take appropriate action.
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Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You may want to put winter emergency
supplies in your vehicle.
Also seeTires on page 550.Include an ice scraper, a small brush or broom, a
supply of windshield washer uid, a rag, some
winter outer clothing, a small shovel, a ashlight, a
red cloth, and reective warning triangles. And,
if you will be driving under severe conditions,
include a small bag of sand, a piece of old carpet,
or a couple of burlap bags to help provide
traction. Be sure you properly secure these items
in your vehicle.
Driving on Snow or Ice
Most of the time, those places where the tires
meet the road probably have good traction.
However, if there is snow or ice between the tires
and the road, you can have a very slippery
situation. You will have a lot less traction, or grip,
and will need to be very careful.
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What is the worst time for this? Wet ice. Very cold
snow or ice can be slick and hard to drive on.
But wet ice can be even more trouble because it
may offer the least traction of all. You can get
wet ice when it is about freezing, 32°F (0°C), and
freezing rain begins to fall. Try to avoid driving
on wet ice until salt and sand crews can get there.Whatever the condition — smooth ice, packed,
blowing, or loose snow — drive with caution.
StabiliTrak
®will improve your ability to accelerate
when driving on a slippery road. But you can
turn StabiliTrak
®off if you ever need to. See
StabiliTrak®System on page 381andIf Your
Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 422. Even with StabiliTrak
®, you will want to
slow down and adjust your driving to the road
conditions. Under certain conditions, you may want
to turn StabiliTrak
®off, such as when driving
through deep snow and loose gravel, to help
maintain vehicle motion at lower speeds.
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The Anti-Lock Brake System (ABS) improves your
vehicle’s stability when you make a hard stop
on a slippery road. Even though you have ABS,
you will want to begin stopping sooner than
you would on dry pavement. SeeAnti-Lock Brake
System (ABS) on page 379.
Allow greater following distance on any
slippery road.
Watch for slippery spots. The road might be
ne until you hit a spot that is covered with
ice. On an otherwise clear road, ice patches
may appear in shaded areas where the
sun cannot reach, such as around clumps of
trees, behind buildings, or under bridges.
Sometimes the surface of a curve or an
overpass may remain icy when the
surrounding roads are clear. If you see a
patch of ice ahead of you, brake before you
are on it. Try not to brake while you are
actually on the ice, and avoid sudden steering
maneuvers.
If You Are Caught in a Blizzard
If you are stopped by heavy snow, you could be in
a serious situation. You should probably stay
with your vehicle unless you know for sure that you
are near help and you can hike through the
snow. Here are some things to do to summon
help and keep yourself and your passengers safe:
Turn on your hazard ashers.
Tie a red cloth to your vehicle to alert police
that you have been stopped by the snow.
Put on extra clothing or wrap a blanket
around you. If you do not have blankets or
extra clothing, make body insulators from
newspapers, burlap bags, rags, oor
mats — anything you can wrap around yourself
or tuck under your clothing to keep warm.
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You can run the engine to keep warm, but be
careful.
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO
(carbon monoxide) gas to get inside. CO
could overcome you and kill you. You
cannot see it or smell it, so you might not
know it is in your vehicle. Clear away
snow from around the base of your
vehicle, especially any that is blocking the
exhaust pipe. And check around again
from time to time to be sure snow does
not collect there.
Open a window just a little on the side of
the vehicle that is away from the wind.
This will help keep CO out.
Run your engine only as long as you must. This
saves fuel. When you run the engine, make it go a
little faster than just idle. That is, push the
accelerator slightly. This uses less fuel for the
heat that you get and it keeps the battery charged.
421

You will need a well-charged battery to restart the
vehicle, and possibly for signaling later on with
your headlamps. Let the heater run for a while.
Then, shut the engine off and close the window
almost all the way to preserve the heat. Start
the engine again and repeat this only when you
feel really uncomfortable from the cold. But do it as
little as possible. Preserve the fuel as long as
you can. To help keep warm, you can get out of
the vehicle and do some fairly vigorous exercises
every half hour or so until help comes.
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
In order to free your vehicle when it is stuck, you
need to spin the wheels, but you do not want
to spin the wheels too fast. The method known as
rocking can help you get out when you are
stuck, but you must use caution.
{CAUTION:
If you let your vehicle’s tires spin at high
speed, they can explode, and you or
others could be injured. And, the
transmission or other parts of the vehicle
can overheat. That could cause an engine
compartment re or other damage. When
you are stuck, spin the wheels as little as
possible. Do not spin the wheels above
35 mph (55 km/h) as shown on the
speedometer.
422

Notice:Spinning the wheels can destroy parts
of your vehicle as well as the tires. If you
spin the wheels too fast while shifting
the transmission back and forth, you can
destroy the transmission.
For information about using tire chains on your
vehicle, seeTire Chains on page 574.
Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right.
That will clear the area around the front wheels. If
you have a four-wheel-drive vehicle, shift into
Four-Wheel High. If your vehicle has StabiliTrak
®,
you should turn the system off. SeeStabiliTrak®
System on page 381. Then shift back and
forth between REVERSE (R) and a forward gear,
spinning the wheels as little as possible.Release the accelerator pedal while you shift, and
press lightly on the accelerator pedal when the
transmission is in gear. By slowly spinning
the wheels in the forward and reverse directions,
you will cause a rocking motion that may free
your vehicle. If that does not get your vehicle out
after a few tries, it may need to be towed out.
Or, you can use the recovery hooks if your vehicle
has them. If your vehicle does need to be towed
out, seeTowing Your Vehicle on page 439.
423

Recovery Hooks
{CAUTION:
These hooks, when used, are under a lot
of force. Always pull the vehicle straight
out. Never pull on the hooks at a
sideways angle. The hooks could break
off and you or others could be injured
from the chain or cable snapping back.
Notice:Never use recovery hooks to tow the
vehicle. Your vehicle could be damaged
and it would not be covered by warranty.
Your vehicle may have recovery hooks at the front
of the vehicle. You may need to use them if you
are stuck off-road and need to be pulled to
some place where you can continue driving.
424