2008 GMC SIERRA Owner's Manual

Radio Reception
Frequency interference and static can occur during
normal radio reception if items such as cell phone
chargers, vehicle convenience accessories, and external
electronic devices are plugged into the accessory
power outlet. If there is interference or static, unplug the
item from the accessory power outlet.
AM
The range for most AM stations is greater than for FM,
especially at night. The longer range can cause
station frequencies to interfere with each other. For
better radio reception, most AM radio stations boost the
power levels during the day, and then reduce these
levels during the night. Static can also occur when things
like storms and power lines interfere with radio
reception. When this happens, try reducing the treble on
your radio.
FM Stereo
FM stereo gives the best sound, but FM signals only
reach about 10 to 40 miles (16 to 65 km). Tall buildings
or hills can interfere with FM signals, causing the
sound to fade in and out.
XM™ Satellite Radio Service
XM™ Satellite Radio Service gives digital radio
reception from coast-to-coast in the 48 contiguous
United States, and in Canada. Just as with FM,
tall buildings or hills can interfere with satellite radio
signals, causing the sound to fade in and out. In
addition, traveling or standing under heavy foliage,
bridges, garages, or through tunnels could cause loss of
the XM signal for a period of time. The radio may
display NO XM SIGNAL to indicate interference.
3-125

Fixed Mast Antenna
The xed mast antenna can withstand most car washes
without being damaged. If the mast should ever
become slightly bent, straighten it out by hand. If the
mast is badly bent, replace it.
Check occasionally to make sure the mast is still
tightened to its base. If tightening is required, tighten by
hand, then with a wrench one quarter turn.
XM™ Satellite Radio Antenna
System
The XM™ Satellite Radio antenna is located on the roof
of your vehicle. Keep this antenna clear of snow and
ice build up for clear radio reception.
If your vehicle has a sunroof, the performance of the
XM™ system may be affected if the sunroof is open.
Loading items onto the roof of your vehicle can interfere
with the performance of the XM™ system. Make sure
the XM™ Satellite Radio antenna is not obstructed.
3-126

Your Driving, the Road, and Your Vehicle..........4-2
Defensive Driving...........................................4-2
Drunk Driving.................................................4-2
Control of a Vehicle........................................4-3
Braking.........................................................4-3
Antilock Brake System (ABS)...........................4-4
Braking in Emergencies...................................4-5
Locking Rear Axle..........................................4-5
StabiliTrak
®System........................................4-6
Steering........................................................4-8
Off-Road Recovery.......................................4-10
Passing.......................................................4-11
Loss of Control.............................................4-11
Off-Road Driving...........................................4-12
Driving at Night............................................4-27
Driving in Rain and on Wet Roads..................4-28
Before Leaving on a Long Trip.......................4-29Highway Hypnosis........................................4-29
Hill and Mountain Roads................................4-30
Winter Driving..............................................4-31
If Your Vehicle is Stuck in Sand, Mud,
Ice, or Snow.............................................4-34
Rocking Your Vehicle to Get It Out.................4-34
Recovery Hooks...........................................4-35
Loading Your Vehicle....................................4-36
Adding a Snow Plow or Similar Equipment.......4-43
Truck-Camper Loading Information..................4-47
Pickup Conversion to Chassis Cab..................4-50
Towing..........................................................4-50
Towing Your Vehicle.....................................4-50
Recreational Vehicle Towing...........................4-50
Towing a Trailer...........................................4-55
Trailer Recommendations...............................4-94
Section 4 Driving Your Vehicle
4-1

Your Driving, the Road, and
Your Vehicle
Defensive Driving
Defensive driving means “always expect the
unexpected.” The rst step in driving defensively is to
wear your safety belt — SeeSafety Belts: They Are for
Everyone on page 1-14.
{CAUTION:
Assume that other road users (pedestrians,
bicyclists, and other drivers) are going to be
careless and make mistakes. Anticipate what
they might do and be ready. In addition:
Allow enough following distance between
you and the driver in front of you.
Focus on the task of driving.
Driver distraction can cause collisions
resulting in injury or possible death. These
simple defensive driving techniques could
save your life.
Drunk Driving
{CAUTION:
Drinking and then driving is very dangerous.
Your reexes, perceptions, attentiveness,
and judgment can be affected by even a
small amount of alcohol. You can have a
serious — or even fatal — collision if you drive
after drinking. Do not drink and drive or ride
with a driver who has been drinking. Ride
home in a cab; or if you are with a group,
designate a driver who will not drink.
Death and injury associated with drinking and driving is
a global tragedy.
Alcohol affects four things that anyone needs to drive a
vehicle: judgment, muscular coordination, vision, and
attentiveness.
Police records show that almost 40 percent of all motor
vehicle-related deaths involve alcohol. In most cases,
these deaths are the result of someone who was drinking
and driving. In recent years, more than 17,000 annual
motor vehicle-related deaths have been associated with
the use of alcohol, with about 250,000 people injured.
4-2

For persons under 21, it is against the law in every
U.S. state to drink alcohol. There are good medical,
psychological, and developmental reasons for
these laws.
The obvious way to eliminate the leading highway
safety problem is for people never to drink alcohol and
then drive.
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.
Control of a Vehicle
The following three systems help to control your vehicle
while driving — brakes, steering, and accelerator. At
times, as when driving on snow or ice, it is easy to ask
more of those control systems than the tires and
road can provide. Meaning, you can lose control of your
vehicle. SeeStabiliTrak
®System on page 4-6.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-4.
Braking
SeeBrake System Warning Light on page 3-44.
Braking action involves perception time and reaction
time. First, you have to decide to push on the brake
pedal. That is perception time. Then you have to bring
up your foot and do it. That is reaction time.
Average reaction time is about three-fourths of a
second. But that is 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 three-fourths 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 is pavement
or gravel; the condition of the road, whether it is
wet, dry, or icy; tire tread; the condition of the brakes;
the weight of the vehicle; and the amount of brake
force applied.
4-3

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. The brakes might not have time to cool
between hard stops. The 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 vehicle’s engine ever stops while you are driving,
brake normally but do not pump the brakes. If you do,
the pedal could get harder to push down. If the
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 can take longer to stop and
the brake pedal will be harder to push.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-4.Antilock Brake System (ABS)
Your vehicle has the Antilock Brake System (ABS), an
advanced electronic braking system that will help
prevent a braking skid.
When you start the engine and begin to drive away, ABS
will check itself. You might hear a momentary motor or
clicking noise while this test is going on. This is normal.
If there is a problem with
ABS, this warning light will
stay on. SeeAntilock
Brake System Warning
Light on page 3-45.
Along with ABS, your vehicle has a Dynamic Rear
Proportioning (DRP) system. If there is a DRP problem,
both the brake and ABS warning lights come on
accompanied by a 10-second chime. The lights and
chime will come on each time the ignition is turned on
until the problem is repaired. See your dealer/retailer for
service.
4-4

Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down. If
one of the wheels is about to stop rolling, the computer
will separately work the brakes at each front wheel
and at both rear wheels.
ABS can change the brake pressure faster than any
driver could. The computer is programmed to make the
most of available tire and road conditions. This can
help you steer around the obstacle while braking hard.
As you brake, the computer keeps receiving updates
on wheel speed and controls braking pressure
accordingly.
Remember: ABS does not change the time you need to
get your foot up to the brake pedal or always decrease
stopping distance. If you get too close to the vehicle
in front of you, you will not have time to apply the brakes
if that vehicle suddenly slows or stops. Always leave
enough room up ahead to stop, even though you
have ABS.Using ABS
Do not pump the brakes. Just hold the brake pedal
down rmly and let antilock work for you. You might
feel the brakes vibrate or notice some noise, but this
is normal.
Braking in Emergencies
With ABS, you can steer and brake at the same time.
In many emergencies, steering can help you more than
even the very best braking.
Locking Rear Axle
If your vehicle has this feature, your locking rear axle
can give you additional traction on snow, mud, ice, sand
or gravel. It works like a standard axle most of the
time, but when one of the rear wheels has no traction
and the other does, this feature will allow the wheel with
traction to move the vehicle.
4-5

StabiliTrak®System
Your vehicle may have the StabiliTrak®system which
combines antilock brake, traction and stability control
systems and helps the driver maintain directional control
of the vehicle in most driving conditions.
When you rst start your vehicle and begin to drive away,
the system performs several diagnostic checks to ensure
there are no problems. You may hear or feel the system
working. This is normal and does not mean there is a
problem with your vehicle. The system should initialize
before the vehicle reaches 20 mph (32 km/h). In some
cases, it may take approximately two miles of driving
before the system initializes.
If the system fails to turn on or activate, the StabiliTrak
®
light along with one of the following messages will be
displayed on the Driver Information Center (DIC):
TRACTION CONTROL OFF, SERVICE TRACTION
CONTROL, STABILITRAK OFF, SERVICE
STABILITRAK. If these DIC messages appear, make
sure the StabiliTrak
®system has not been turned
off using the StabiliTrak®on/off button.Then turn the steering wheel clockwise from the nine
o’clock position to the three o’clock position. If this clears
the message(s), your vehicle does not need servicing.
If this does not clear the message(s), then turn the
vehicle off, wait 15 seconds, and then turn it back on
again to reset the system. If any of these messages still
appear on the Driver Information Center (DIC), your
vehicle should be taken in for service. For more
information on the DIC messages, seeDriver
Information Center (DIC) on page 3-54.
The StabiliTrak
®light will
ash on the instrument
panel cluster when
the system is both on and
activated.
You may also feel or hear the system working; this is
normal.
4-6