wheel GMC SIERRA 2004 Service Manual

{CAUTION:
Your brake system may not be working
properly if the SERVICE BRAKE BOOSTER
message is displayed.
If the brake system warning light is also on, you
should have the vehicle towed for service. See
ªBrake System Warning Lightº in the Index.
If the brake system warning light isn't on, you
still have brakes, but the supplemental brake
assist system may not operate properly. In the
event of a vacuum loss, you may not have
vacuum power assist for braking. The brake
pedal will be harder to push and it will take
longer to stop. If you continue to drive with this
message displayed it can lead to a crash. Have
the brake system serviced as soon as possible.
SERVICE 4 WHEEL STEER
If a problem occurs with the 4 wheel steer system, this
message will appear on the DIC. If this message
appears, stop as soon as possible, and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed,
or appears again when you being driving, the four wheel
steer system needs service.
SERVICE 4WD
If a problem occurs with the four wheel drive system,
this message will appear on the DIC. If this message
appears, stop as soon as possible and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed,
or appears again when you begin driving, the four wheel
drive system needs service.
SERVICE RIDE CONTROL
If a problem occurs with the suspension system, this
message will appear on the DIC. If this message
appears, stop and turn off the vehicle. Restart the
vehicle and check for the message on the DIC display.
If the message is still displayed, or appears again
when you begin driving, the air suspension system
needs service.
3-71

TIGHTEN FUEL CAP
If the vehicle's fuel cap is not tightened properly thsi
message may appear along with the check engine light
on the instrument panel. See
Malfunction Indicator
Lamp on page 3-49. Fully reinstall the fuel cap.
SeeFilling Your Tank on page 5-7. The diagnostic
system can determine if the fuel cap has been left off or
improperly installed. A loose or missing fuel cap will
allow fuel to evaporate into the atmosphere. A few
driving trips with the cap properly installed should turn
the light and message off.
TRACTION ACTIVE
When the traction control system had detected that any
of the vehicle's wheels are slipping, the traction
control system will activate and this message will appear
on the DIC. For more information see ªTraction Assistº
in the Index.
TRANSMISSION HOT
If the transmission ¯uid temperature becomes high, the
message center will display this message.
When the transmission enters the protection mode, you
may notice a change in the transmission shifting
patterns. When the transmission ¯uid temperature
returns to normal, the display will turn off and the
transmission shifting patterns will return to normal.
Notice:If you drive your vehicle while the
transmission ¯uid is overheating and the
transmission temperature warning is displayed on
the instrument panel cluster and/or DIC, you
can damage the transmission. This could lead to
costly repairs that would not be covered by
your warranty. Do not drive your vehicle with
overheated transmission ¯uid or while transmission
temperature warning is displayed.
The following situations can cause the transmission to
operate at higher temperatures:
·Towing a trailer
·Hot outside air temperatures
·Hauling a large or heavy load
·Low transmission ¯uid level
·High transmission ¯uid level
·Restricted air ¯ow to the radiator and the auxiliary
transmission oil cooler.
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, see
Scheduled Maintenance
on page 6-4for the proper transmission maintenance
intervals.
3-72

Audio Steering Wheel Controls
You can control certain radio functions using the buttons
on your steering wheel.
g(OnStar/Voice Recognition):If your vehicle has
OnStarž, you can press this button to interact with
the OnStaržsystem. See the OnStaržmanual provided
with your vehicle for more information.
If your vehicle does not have OnStar
ž, pressing this
button will mute the audio system.PROG (Program):Press this button to play a station
you have programmed on the radio preset pushbuttons
on the selected band.
If a cassette tape is playing, press this button to play
the other side of the tape.
If a CD is playing in the CD changer, press this button
to go to the next available CD.
QSOURCER:Press this button to select FM1,
FM2, AM, or XM1 or XM2, (48 contiguous US states, if
equipped), or a cassette tape or CD. The cassette
or CD must be loaded to play. Available loaded sources
are shown on the display as a tape or a CD symbol.
QSEEKR:Press the up or the down arrow to go to
the next or to the previous radio station and stay
there.
If a cassette tape or CD is playing, the player will
advance with the up arrow and reverse with the down
arrow.
QVOLR(Volume):Press the up or the down arrow
to increase or to decrease volume.
3-128

Your Driving, the Road, and Your Vehicle..........4-2
Defensive Driving...........................................4-2
Drunken Driving.............................................4-2
Control of a Vehicle........................................4-5
Braking.........................................................4-6
Traction Assist System (TAS)...........................4-9
Manual Selectable Ride.................................4-11
Locking Rear Axle........................................4-12
Steering......................................................4-12
QUADRASTEERŸ........................................4-14
Off-Road Recovery.......................................4-17
Passing.......................................................4-17
Loss of Control.............................................4-18
Off-Road Driving with Your Four-Wheel-Drive
Vehicle....................................................4-20
Driving at Night............................................4-37
Driving in Rain and on Wet Roads..................4-39
City Driving..................................................4-42Freeway Driving...........................................4-43
Before Leaving on a Long Trip.......................4-44
Highway Hypnosis........................................4-44
Hill and Mountain Roads................................4-45
Winter Driving..............................................4-47
If You Are Stuck: In Sand, Mud, Ice or Snow . . .4-51
Towing..........................................................4-53
Towing Your Vehicle.....................................4-53
Recreational Vehicle Towing...........................4-54
Loading Your Vehicle....................................4-57
Adding a Snow Plow or Similar Equipment.......4-64
Truck-Camper Loading Information..................4-68
Trailer Recommendations...............................4-70
Pickup Conversion to Chassis Cab..................4-70
Towing a Trailer...........................................4-70
Power Take-Off (PTO).................................4-101
Section 4 Driving Your Vehicle
4-1

Anti-lock Brake System
Your vehicle has anti-lock brakes. ABS is an advanced
electronic braking system that will help prevent a
braking skid.
When you start your engine and begin to drive away,
your anti-lock brake system will check itself. You
may hear a momentary motor or clicking noise while
this test is going on. This is normal.
If there is a problem with
the anti-lock brake system,
this warning light will
stay on. See
Anti-Lock
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 will 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 for
service.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's 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.
4-7

The anti-lock system 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, your computer keeps receiving updates
on wheel speed and controls braking pressure
accordingly.Remember: Anti-lock 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
your brakes if that vehicle suddenly slows or stops.
Always leave enough room up ahead to stop, even
though you have anti-lock brakes.
Using Anti-Lock
Do not pump the brakes. Just hold the brake pedal
down ®rmly and let anti-lock work for you. You may feel
the brakes vibrate, or you may notice some noise,
but this is normal.
Braking in Emergencies
With anti-lock, you can steer and brake at the same
time. In many emergencies, steering can help you more
than even the very best braking.
4-8

Traction Assist System (TAS)
Your vehicle may have a Traction Assist System (TAS)
that limits wheel spin. This is especially useful in
slippery road conditions. The system operates only if it
senses that one or both of the rear wheels are
spinning or beginning to lose traction. When this
happens, the system reduces engine power to limit
wheel spin.
The traction control system is enabled every time your
vehicle is started. The system will activate if it senses
that any of the wheels are spinning or beginning to lose
traction.
You may hear or feel the system working or notice a
lack of accelerator response, but this is normal.
The Traction Assist System may operate on dry roads
under some conditions. When this happens, you
may notice a reduction in acceleration. This is normal
and doesn't mean there's a problem with your vehicle.
Examples of these conditions include a hard
acceleration in a turn, an abrupt upshift or downshift of
the transmission or driving on rough roads.
If your vehicle is in cruise control when the TAS begins
to limit wheel spin, the cruise control will automatically
disengage. When road conditions allow you to safelyuse it again, you may re-engage the cruise control. See
Cruise ControlunderTurn Signal/Multifunction Lever
on page 3-7.
When the traction off light
is on, the TAS is off and
will not limit wheel
spin. Adjust your driving
accordingly.
The traction off light will come on under the following
conditions:
·The Traction Assist System is turned off, either by
pressing the TAS on/off button or by turning off
the automatic engagement feature of the TAS.
·The transmission is in FIRST (1); TAS will not
operate in this gear. This is normal.
·The vehicle is driven on an extremely rough road.
When the vehicle leaves the rough surface, slows
down or stops, the light will go off and TAS will
be on again. This is normal.
4-9

·A Traction Assist System, Anti-Lock Brake System
or engine-related problem has been detected and
the vehicle needs service.
·If the vehicle has been driven with the TAS system
on for long periods of time, or if the vehicle has
gone through many several high speed braking
maneuvers the system may be automatically
disabled. The system will automatically re-enable
after approximately two minutes of not using
the brakes.
See
Traction Off Light on page 3-45.
The Traction Assist System, as delivered from the
factory, will automatically come on whenever you start
your vehicle. To limit wheel spin, especially in
slippery road conditions, you should always leave the
system on. But you can turn the TAS off if you ever need
to. You should turn the TAS off if your vehicle ever
gets stuck in sand, mud or snow and rocking the vehicle
is required. See
Rocking Your VehicleunderIf You
Are Stuck: In Sand, Mud, Ice or Snow on page 4-51.To turn the system on or
off press the TAS on/off
button located on the
instrument panel.
If you used the button to turn the system off, the traction
off light will come on and stay on. You can turn the
system back on at any time by pressing the button
again. The traction off light should go off.
If desired, you can change the TAS automatic
engagement feature so that the system will not come on
automatically when the engine is started. To do so:
1. Park the vehicle with the ignition off and the
transmission in PARK (P).
2. Turn the ignition to RUN; do not start the engine.
3. Apply the brake pedal, shift into NEUTRAL (N),
press the accelerator pedal to the ¯oor, then
press the TAS on/off button and hold it down for at
least six seconds.
4. Release the TAS button and both pedals.
5. Turn off the ignition and wait a few seconds.
4-10

FIRM (Loaded):Press the button to activate this
setting, the indicator light will be lit. Use this setting to
minimize trailer inputs to the vehicle or when the vehicle
is fully loaded. This setting is also appropriate for
off-road driving.
You can select a setting at any time based on road and
trailering conditions to provide the best ride and
handling. Select a new setting whenever driving
conditions change.
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.
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
Driving on Curves
It is important to take curves at a reasonable speed.
A lot of the ªdriver lost controlº 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 your 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.
Suppose you are steering through a sharp curve.
Then you suddenly accelerate. Both control
systems Ð steering and acceleration Ð have to do their
work where the tires meet the road. Adding the
sudden acceleration can demand too much of those
places. You can lose control. See
Traction Assist
System (TAS) on page 4-9.
4-12

What should you do if this ever happens? Ease up on
the accelerator pedal, steer the vehicle the way you
want it to go, and slow down.
Speed limit signs near curves warn that you should
adjust your speed. Of course, the posted speeds
are based on good weather and road conditions. Under
less favorable conditions you will want to go slower.
If you need to reduce your speed as you approach
a curve, do it before you enter the curve, while your front
wheels are straight ahead.
Try to adjust your speed so you can ªdriveº through the
curve. Maintain a reasonable, steady speed. Wait to
accelerate until you are out of the curve, and then
accelerate gently into the straightaway.
Steering in Emergencies
There are times when steering can be more effective
than braking. For example, you come over a hill and ®nd
a truck stopped in your lane, or a car suddenly pulls
out from nowhere, or a child darts out from between
parked cars and stops right in front of you. You
can avoid these problems by braking Ð if you can stop
in time. But sometimes you can not; there is not
room. That is the time for evasive action Ð steering
around the problem.
Your vehicle can perform very well in emergencies like
these. First apply your brakes.See
Braking on page 4-6. It is better to remove as much
speed as you can from a possible collision. Then
steer around the problem, to the left or right depending
on the space available.
An emergency like this requires close attention and a
quick decision. If you are holding the steering wheel at
the recommended 9 and 3 o'clock positions, you
can turn it a full 180 degrees very quickly without
removing either hand. But you have to act fast, steer
quickly, and just as quickly straighten the wheel
once you have avoided the object.
The fact that such emergency situations are always
possible is a good reason to practice defensive driving
at all times and wear safety belts properly.
4-13