change wheel GMC SIERRA 2008 Owner's Manual

Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may keep the airbag system from
working properly. Changing or moving any parts
of the front seats, safety belts, the airbag sensing
and diagnostic module, steering wheel, instrument
panel, roof-rail airbag modules, ceiling headliner
or pillar garnish trim, overhead console, front
sensors, rollover sensor module, or airbag wiring
can affect the operation of the airbag system.
In addition, your vehicle may have a passenger
sensing system for the right front passenger’s
position, which includes sensors that are part of the
passenger’s seat. The passenger sensing system
may not operate properly if the original seattrim is replaced with non-GM covers, upholstery or
trim, or with GM covers, upholstery or trim
designed for a different vehicle. Any object, such as
an aftermarket seat heater or a comfort enhancing
pad or device, installed under or on top of the
seat fabric, could also interfere with the operation of
the passenger sensing system. This could either
prevent proper deployment of the passenger
airbag(s) or prevent the passenger sensing system
from properly turning off the passenger airbag(s).
SeePassenger Sensing System on page 1-80.
If you have any questions about this, you should
contact Customer Assistance before you modify
your vehicle. The phone numbers and addresses for
Customer Assistance are in Step Two of the
Customer Satisfaction Procedure in this manual.
SeeCustomer Satisfaction Procedure on page 7-2.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-86
for additional important information.
1-85

In some cases, this could appear to be a delayed shift,
however the transmission is operating normally.
Your vehicle’s transmission uses adaptive shift controls.
Adaptive shift controls continually compares key shift
parameters to pre-programmed ideal shifts stored in the
transmissions computer. The transmission constantly
makes adjustments to improve vehicle performance
according to how the vehicle is being used, such as with
a heavy load or when temperature changes. During this
adaptive shift control process, shifting might feel different
as the transmission determines the best settings.
When temperatures are very cold, the Allison
Transmission
®and Hydra-Matic®6-Speed
transmission’s gear shifting could be delayed providing
more stable shifts until the engine warms up. Shifts
could be more noticeable with a cold transmission. This
difference in shifting is normal.
MANUAL MODE (M):This position, is available on
vehicles with the Allison Transmission
®or Hydra-Matic®
6-Speed transmission. It lets drivers select the range
of gears appropriate for current driving conditions. If your
vehicle has this feature, see Range Select Mode
(Allison Transmission
®or Hydra-Matic®6-Speed
transmission) later in this section.THIRD (3):This position is also used for normal driving.
It reduces vehicle speed more than DRIVE (D) without
using the brakes. You might choose THIRD (3)
instead of DRIVE (D) when driving on hilly, winding
roads, when towing a trailer, so there is less shifting
between gears and when going down a steep hill.
SECOND (2):This position reduces vehicle speed even
more than THIRD (3) without using your brakes. 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 the brakes off and on.
If you manually select SECOND (2) in an automatic
transmission, the transmission will start in second gear.
You can 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.
FIRST (1):For the Hydra-Matic
®4-Speed transmission
this position reduces vehicle speed even more than
SECOND (2) without using the brakes. 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 does not shift into rst gear
until the vehicle is going slowly enough.
2-31

To use this feature, do the following:
1. Move the shift lever to the MANUAL MODE (M).
2. Press the plus/minus buttons, located on the
steering column shift lever, to select the desired
range of gears for your current driving conditions.
When MANUAL MODE (M) is selected a number
displays next to the M, indicating the current gear.
This number is the highest gear that can be used.
However, your vehicle can automatically shift to lower
gears as it adjusts to driving conditions. This means that
all gears below that number are available. When
FIFTH (5) is selected, FIRST (1) through FIFTH (5)
gears are automatically shifted by the vehicle, but
SIXTH (6) cannot be used until the plus/minus button
located on the steering column lever is used to change
to the gear.
Grade Braking is not available when the Range
Selection Mode is active. SeeTow/Haul Mode on
page 2-34.While using the Range Selection mode feature, cruise
control and the Tow/Haul mode can be used.
Notice:Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator
pedal may damage the transmission. The repair will
not be covered by your warranty. If you are stuck,
do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
Low Traction Mode
If your vehicle has the Allison Transmission®,orthe
Hydra-Matic®6-Speed Automatic Transmission, it has a
Low Traction Mode that assist in vehicle acceleration
when road conditions are slippery, such as with ice
or snow. While the vehicle is at a stop, select the second
gear range using the Range Selection system. This
will limit torque to the wheels after it detects wheel slip,
preventing the tires from spinning.
2-33

Instrument Panel Overview...............................3-4
Instrument Panel Overview
(Base/Uplevel version).................................3-4
Instrument Panel Overview
(Premium version).......................................3-6
Hazard Warning Flashers................................3-8
Other Warning Devices...................................3-8
Horn.............................................................3-8
Tilt Wheel.....................................................3-9
Turn Signal/Multifunction Lever.........................3-9
Turn and Lane-Change Signals.......................3-10
Headlamp High/Low-Beam Changer.................3-11
Flash-to-Pass...............................................3-11
Windshield Wipers........................................3-12
Rainsense™ II Wipers...................................3-12
Windshield Washer.......................................3-13
Cruise Control..............................................3-14
Exterior Lamps.............................................3-17
Headlamps on Reminder................................3-18
Daytime Running Lamps (DRL).......................3-18
Automatic Headlamp System..........................3-19
Puddle Lamps..............................................3-20
Fog Lamps..................................................3-20
Auxiliary Roof Mounted Lamp.........................3-20Instrument Panel Brightness...........................3-21
Dome Lamps...............................................3-21
Dome Lamp Override....................................3-21
Entry Lighting...............................................3-21
Exit Lighting.................................................3-21
Reading Lamps............................................3-22
Cargo Lamp.................................................3-22
Electric Power Management...........................3-22
Battery Run-Down Protection..........................3-23
Accessory Power Outlet(s).............................3-23
Ashtray(s) and Cigarette Lighter......................3-24
Climate Controls............................................3-25
Climate Control System
(With Air Conditioning)...............................3-25
Climate Control System (Heater Only)..............3-27
Dual Automatic Climate Control System...........3-28
Outlet Adjustment.........................................3-33
Warning Lights, Gages, and Indicators............3-34
Instrument Panel Cluster................................3-35
Speedometer and Odometer...........................3-36
Trip Odometer..............................................3-36
Tachometer.................................................3-36
Safety Belt Reminders...................................3-37
Section 3 Instrument Panel
3-1

Tilt Wheel
The tilt wheel lets you adjust the steering wheel before
you drive. Raise it to the highest level to give your
legs more room when exiting or entering the vehicle.
The tilt steering wheel lever is located on the lower left
side of the steering column.
To tilt the wheel, hold the steering wheel and pull the
lever. Then move the steering wheel to a comfortable
position and release the lever to lock the wheel in place.
Turn Signal/Multifunction Lever
The lever on the left side of the steering column
includes the following:
GTurn and Lane Change Signals. SeeTurn and
Lane-Change Signals on page 3-10.
53Headlamp High/Low-Beam Changer. See
Headlamp High/Low-Beam Changer on page 3-11.
Flash-to-Pass. SeeFlash-to-Pass on page 3-11.
NWindshield Wipers. SeeWindshield Wipers on
page 3-12.
LWindshield Washer. SeeWindshield Washer
on page 3-13.
For information on the exterior lamps, seeExterior
Lamps on page 3-17.
3-9

Cruise Control
{CAUTION:
Cruise control can be dangerous where you
cannot drive safely at a steady speed. So, do
not 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 excessive wheel slip, and
you could lose control. Do not use cruise
control on slippery roads.
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).
When you apply your brakes, cruise control is turned off.
If your vehicle has an Allison
®automatic transmission,
see “Grade Braking and Cruise Grade Braking
(Allison Transmission
®) underTow/Haul Mode onpage 2-34for an explanation of how cruise control
interacts with the Range Selection Mode, tow/haul and
grade braking systems.
If your vehicle has the StabiliTrak
®™ system and
begins to limit wheel spin while you are using cruise
control, the cruise control will automatically disengage.
SeeStabiliTrak
®System on page 4-6. When road
conditions allow you to safely use it again, you may turn
the cruise control back on.
The cruise control buttons
are located on left side of
the steering wheel.
T(On/Off):This button can both activate and turn
off the system. The indicator light is on when cruise
control is on and turns off when cruise control is off.
3-14

Erasing Speed Memory
When the cruise control or the ignition is turned off, the
cruise control set speed memory is erased.
Exterior Lamps
The exterior lamps control
is located on the
instrument panel to the left
of the steering wheel.
It controls the following systems:
Headlamps
Taillamps
Parking Lamps
License Plate Lamps
Instrument Panel LightsThe exterior lamps control has four positions:
O(Off):Turn the control to this position to turn off the
automatic headlamps and daytime running lamps
(DRL). Turn the headlamp control to the off position
again to turn the automatic headlamps or DRL back on.
For vehicles rst sold in Canada, the off position will
only work when the vehicle is shifted into PARK (P).
AUTO (Automatic):Turn the control to this position to
automatically turn on the headlamps at normal
brightness, together with the following:
Parking Lamps
Instrument Panel Lights
Taillamps
License Plate Lamps
When the vehicle is turned off and the headlamps are in
AUTO, the headlamps may automatically remain on
for a set time. The time of the delay can be changed
using the DIC. SeeDriver Information Center (DIC) on
page 3-54.
3-17

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

In this mode, engine power is not reduced automatically
and the driven wheels can spin more freely. This can
cause the brake-traction control to activate constantly.
Notice:If you allow the wheel(s) of one axle to spin
excessively while the StabiliTrak
®, ABS and brake
warning lights and the SERVICE STABILITRAK
message are displayed, you could damage the
transfer case. The repairs would not be covered by
your warranty. Reduce engine power and do not
spin the wheel(s) excessively while these lights and
this message are displayed.
The traction control system may activate on dry or
rough roads or under conditions such as heavy
acceleration while turning or abrupt upshifts/downshifts
of the transmission. When this happens, you may
notice a reduction in acceleration, or may hear a noise
or vibration. This is normal.
If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will ash and the cruise
control will automatically disengage. When road
conditions allow you to use cruise again, you may
re-engage the cruise control. SeeCruise Control on
page 3-14.
StabiliTrak
®may also turn off automatically if it
determines that a problem exists with the system. If the
problem does not clear itself after restarting the
vehicle, you should see your dealer/retailer for service.
Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer but
it will take much more effort.
Steering Tips
It is important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here is why:
Experienced driver or beginner, each of us is subject to
the same laws of physics when driving on curves.
The traction of the tires against the road surface makes
it possible for the vehicle to change its path when
you turn the front wheels. If there is no traction, inertia
will keep the vehicle going in the same direction. If
you have ever tried to steer a vehicle on wet ice, you
will understand this.
The traction you can get in a curve depends on the
condition of the tires and the road surface, the angle at
which the curve is banked, and your speed. While
you are in a curve, speed is the one factor you
can control.
4-8

Of course, traction is reduced when water, snow, ice,
gravel, or other material is on the road. For safety, you
will want to slow down and adjust your driving to
these conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
While driving on a surface with reduced traction, try your
best to avoid sudden steering, acceleration, or braking,
including reducing vehicle speed by shifting to a lower
gear. Any sudden changes could cause the tires to
slide. You may not realize the surface is slippery until
your vehicle is skidding. Learn to recognize warning
clues — such as enough water, ice, or packed snow on
the road to make a mirrored surface — and slow down
when you have any doubt.
Remember: Any Antilock Brake System (ABS) helps
avoid only the braking skid.Off-Road Driving
This off-road guide is for vehicles that have four-wheel
drive. Also, seeBraking on page 4-3. If your vehicle
does not have four-wheel drive or is equipped with
20-inch tire/wheel assemblies, you should not drive
off-road unless you are on a level, solid surface.
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.
Off-road driving can be great fun. But it does have
some denite hazards. The greatest of these is
the terrain itself.
“Off-roading” means you have left the great
North American road system behind. Traffic lanes
are not marked. Curves are not banked. There are no
road signs. Surfaces can be slippery, rough, uphill,
or downhill. In short, you have gone right back to nature.
Off-road driving involves some new skills. And that is
why it is very important that you read this guide. You will
nd many driving tips and suggestions. These will
help make your off-road driving safer and more
enjoyable.
4-12