weight GMC SIERRA CLASSIC 2007 Owners Manual

Q:What are the different types of add-on
child restraints?
A:Add-on child restraints, which are purchased by
the vehicle’s owner, are available in four basic
types. Selection of a particular restraint should
take into consideration not only the child’s
weight, height, and age but also whether or not
the restraint will be compatible with the motor
vehicle in which it will be used.
For most basic types of child restraints, there
are many different models available. When
purchasing a child restraint, be sure it is
designed to be used in a motor vehicle. If it is,
the restraint will have a label saying that it
meets federal motor vehicle safety standards.
The restraint manufacturer’s instructions that
come with the restraint state the weight and
height limitations for a particular child restraint.
In addition, there are many kinds of restraints
available for children with special needs.
{CAUTION:
Newborn infants need complete support,
including support for the head and neck.
This is necessary because a newborn
infant’s neck is weak and its head weighs
so much compared with the rest of its
body. In a crash, an infant in a rear-facing
seat settles into the restraint, so the crash
forces can be distributed across the
strongest part of an infant’s body, the
back and shoulders. Infants always
should be secured in appropriate infant
restraints.
50

In any particular crash, no one can say whether
an airbag should have inated simply because
of the damage to a vehicle or because of what the
repair costs were. Ination is determined by
what the vehicle hits, the angle of the impact, and
how quickly the vehicle slows down.
The airbag system is designed to work properly
under a wide range of conditions, including off-road
usage. Observe safe driving speeds, especially
on rough terrain. As always, wear your safety belt.
SeeOff-Road Driving on page 372for more tips
on off-road driving.Single Stage vs. Dual Stage Airbags
Depending on the weight of your vehicle, you will
have either “Single Stage Airbags” or “Dual
Stage Airbags.” Vehicles that have a passenger
sensing system also have dual stage airbags.
If the rearview mirror in your vehicle has a
passenger airbag status indicator, your vehicle
has the passenger sensing system and therefore,
it has dual stage airbags. If the rearview mirror
in your vehicle does not have a passenger airbag
status indicator, then your vehicle does not
have the passenger sensing system and it has
single stage airbags. SeePassenger Airbag Status
Indicator on page 250orPassenger Sensing
System on page 103.
Single Stage Airbags
If your vehicle has frontal airbags with single stage
deployment and your vehicle goes straight into
a wall that does not move or deform, the threshold
level is about 13 to 16 mph (20 to 25 km/h). The
threshold level can vary, however, with specic
vehicle design, so that it can be somewhat above
or below this range.
96

A right front passenger takes his/her weight off
of the seat for a period of time.
The right front passenger seat is occupied by
a smaller person, such as a child who has
outgrown child restraints.
Or, if there is a critical problem with the airbag
system or the passenger sensing system.
When the passenger sensing system has turned off
the passenger’s frontal airbag, the off indicator will
light and stay lit to remind you that the airbag is off.
If a child restraint has been installed and the on
indicator is lit, turn the vehicle off. Remove
the child restraint from the vehicle and reinstall the
child restraint following the child restraint
manufacturer’s directions and refer toSecuring a
Child Restraint in the Right Front Seat Position
(Regular and Extended Cab) (With Passenger
Sensing System)in the Index.
If, after reinstalling the child restraint and restarting
the vehicle, the on indicator is still lit, check to
make sure that the vehicle’s seatback is not
pressing the child restraint into the seat cushion. If
this happens, slightly recline the vehicle’s
seatback and adjust the seat cushion if possible.Also make sure the child restraint is not trapped
under the vehicle head restraint. If this happens,
adjust the head restraint.
If the on indicator is still lit, secure the child in the
child restraint in a rear seat position in the vehicle if
one is available and check with your dealer.
The passenger sensing system is designed to
enable (may inate) the right front passenger’s
frontal airbag anytime the system senses
that a person of adult size is sitting properly in the
right front passenger’s seat. When the passenger
sensing system has allowed the airbag to be
enabled, the on indicator will light and stay lit to
remind you that the airbag is active.
For some children who have outgrown child
restraints and for very small adults, the passenger
sensing system may or may not turn off the
right front passenger’s frontal airbag, depending
upon the person’s seating posture and body build.
Everyone in your vehicle who has outgrown
child restraints should wear a safety belt
properly — whether or not there is an airbag for
that person.
106

See “Range Selection Mode” later in this section.
PARK (P):This position locks your rear wheels. It
is the best position to use when you start your
engine because your vehicle cannot move easily. If
your vehicle has the Allison Transmission
®, with the
Power Take-Off (PTO), use PARK (P) when
starting. The Allison Transmission
®has a park pawl
that is designed to hold the weight of commercial
medium duty trucks. Therefore, the Allison
Transmission
®uses larger parts than other
automatic transmissions. These larger parts may
sometimes make a clunking noise when the
selector lever is moved from DRIVE (D) or
REVERSE (R) to PARK (P). This is normal and
there is no damage occurring during these shifts.
When parked on a hill, especially with a heavy load,you may notice an increase in the effort to shift out
of Park. See Torque Lock (Automatic Transmission)
underShifting Into Park (P) (Automatic
Transmission) on page 170for more information.
{CAUTION:
It is dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P)
with the parking brake rmly set. Your
vehicle can roll.
Do not leave your vehicle when the engine
is running unless you have to. If you have
left the engine running, the vehicle can
move suddenly. You or others could be
injured. To be sure your vehicle will not
move, even when you are on fairly level
ground, always set your parking brake
and move the shift lever to PARK (P).
SeeShifting Into Park (P) (Automatic
Transmission) on page 170. If you are
pulling a trailer, seeTowing a Trailer on
page 429.
Allison Transmission®
141

Leaving Your Vehicle With the Engine
Running (Automatic Transmission)
{CAUTION:
It can be dangerous to leave your vehicle
with the engine running. Your vehicle
could move suddenly if the shift lever is
not fully in PARK (P) with the parking
brake rmly set.
If you have four-wheel drive and your
transfer case is in NEUTRAL, your vehicle
will be free to roll, even if your shift lever
is in PARK (P). So be sure the transfer
case is in a drive gear — not in NEUTRAL.
And, if you leave the vehicle with the
engine running, it could overheat and
even catch re. You or others could be
injured. Do not leave your vehicle with the
engine running unless you have to.If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P)
and the parking brake is rmly 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) without rst pulling it toward you.
If you can, it means that the shift lever was
not fully locked into PARK (P).
Torque Lock (Automatic Transmission)
If you are parking on a hill and you do not 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 nd 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, see “Shifting Into
PARK (P)” listed earlier in this section.
When you are ready to drive, move the shift lever
out of PARK (P) before you release the parking
brake.
171

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)
(Automatic Transmission)
Your vehicle has an automatic transmission shift
lock control system which locks the shift lever
in PARK (P) when the ignition is in the LOCK
position. 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 140and “Torque Lock”
underShifting Out of Park (P) (Automatic
Transmission) on page 172.
If your vehicle has an Allison Transmission
®, the
transmission has a park pawl designed to hold the
higher weight of commercial medium duty
trucks. Therefore, the Allison Transmission
®uses
larger parts than other automatic transmissions.
These larger parts may sometimes make a
clunking noise when the selector lever is movedfrom DRIVE (D) or REVERSE (R) to PARK (P).
This is normal and there is no damage occurring
during these shifts.
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
not shift out of PARK (P), try this:
1. Turn the key to ACCESSORY. There is no
shift interlock in this key position.
2. Apply and hold the brake until the end of
Step 4.
3. Shift the transmission to NEUTRAL (N).
4. Start the vehicle and then shift to the gear
you want.
5. Have the system xed as soon as you can.
172

Drunken Driving
Death and injury associated with drinking and
driving is a national tragedy. It is the number
one contributor to the highway death toll,
claiming thousands of victims every year.
Alcohol affects four things that anyone needs to
drive a vehicle:
Judgment
Muscular Coordination
Vision
Attentiveness
Police records show that almost half 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 16,000 annual motor vehicle-related deaths
have been associated with the use of alcohol, with
more than 300,000 people injured.Many adults — by some estimates, nearly half
the adult population — choose never to drink
alcohol, so they never drive after drinking.
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. But what if people do?
How much is “too much” if someone plans
to drive? It is a lot less than many might think.
Although it depends on each person and situation,
here is some general information on the problem.
The Blood Alcohol Concentration (BAC) of
someone who is drinking depends upon
four things:
The amount of alcohol consumed
The drinker’s body weight
The amount of food that is consumed before
and during drinking
The length of time it has taken the drinker to
consume the alcohol
357

According to the American Medical Association,
a 180 lb (82 kg) person who drinks three 12 ounce
(355 ml) bottles of beer in an hour will end up with a
BAC of about 0.06 percent. The person would
reach the same BAC by drinking three 4 ounce
(120 ml) glasses of wine or three mixed drinks if
each had 1-1/2 ounces (45 ml) of liquors like
whiskey, gin, or vodka.It is the amount of alcohol that counts. For example,
if the same person drank three double martinis
(3 ounces or 90 ml of liquor each) within an hour,
the person’s BAC would be close to 0.12 percent.
A person who consumes food just before or during
drinking will have a somewhat lower BAC level.
There is a gender difference, too. Women
generally have a lower relative percentage of
body water than men. Since alcohol is carried in
body water, this means that a woman generally will
reach a higher BAC level than a man of her
same body weight will when each has the same
number of drinks.
The law in most U.S. states, and throughout
Canada, sets the legal limit at 0.08 percent.
In some other countries, the limit is even lower.
For example, it is 0.05 percent in both France
and Germany. The BAC limit for all commercial
drivers in the United States is 0.04 percent.
The BAC will be over 0.10 percent after three to
six drinks (in one hour). Of course, as we have
seen, it depends on how much alcohol is in the
drinks, and how quickly the person drinks them.
358

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 are driving on snow or
ice, it is easy to ask more of those control systems
than the tires and road can provide. That means
you can lose control of your vehicle. SeeTraction
Assist System (TAS) on page 363.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 468.
Braking
SeeBrake System Warning Light on page 254.
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.
360

Driving Across an Incline
Sooner or later, an off-road trail will probably go
across the incline of a hill. If this happens,
you have to decide whether to try to drive across
the incline. Here are some things to consider:
A hill that can be driven straight up or down
may be too steep to drive across. When you go
straight up or down a hill, the length of the
wheel base — the distance from the front
wheels to the rear wheels — reduces the
likelihood the vehicle will tumble end over end.
But when you drive across an incline, the much
more narrow track width — the distance
between the left and right wheels — may not
prevent the vehicle from tilting and rolling over.
Also, driving across an incline puts more weight
on the downhill wheels. This could cause a
downhill slide or a rollover.
Surface conditions can be a problem when you
drive across a hill. Loose gravel, muddy spots,
or even wet grass can cause your tires to slip
sideways, downhill. If the vehicle slips
sideways, it can hit something that will
trip it — a rock, a rut, etc. — and roll over.
Hidden obstacles can make the steepness of
the incline even worse. If you drive across a
rock with the uphill wheels, or if the downhill
wheels drop into a rut or depression, your
vehicle can tilt even more.
For reasons like these, you need to decide
carefully whether to try to drive across an incline.
Just because the trail goes across the incline
does not mean you have to drive it. The last
vehicle to try it might have rolled over.
{CAUTION:
Driving across an incline that is too steep
will make your vehicle roll over. You could
be seriously injured or killed. If you have
any doubt about the steepness of the
incline, do not drive across it. Find another
route instead.
387