2004 GMC SIERRA DENALI instrument panel

Manual Selectable Ride
The main function of this system is to provide superior
ride comfort while trailering or fully loaded, as well
as for unloaded driving. This system also helps
to provide:
·Improved trailering stability
·Improved handling response when trailering or fully
loaded
This button is located
on the center of the
instrument panel near
the radio.
Press it to activate the selectable ride setting as
desired. An indicator light near the button will illuminate
whenever the system is active.
It is recommended to use this system as follows:
·For optimum ride comfort in an unloaded vehicle
the button should be out. The indicator light will
not be lit. This button position indicates NORMAL
levels of ride control or damping.
·For optimum ride comfort when trailering, fully
loaded, driving off-road, or when personal
preferences demand more control, the button
should be pressed in with the indicator light lit.
This switch position indicates FIRM levels of ride
control or damping.
The following guide can also be used to help determine
the best setting.
NORMAL:The indicator light will not be lit when the
system is in this setting. Use for normal city and highway
driving. This setting provides a smooth, soft ride when
the vehicle is unloaded.
FIRM (Unloaded):Press the button to activate this
setting, the indicator light will be lit. Use this setting
when road conditions or personal preference demand
more control. This setting provides more ªfeel²or
response to the road conditions.
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.
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QUADRASTEERŸ
The QUADRASTEERŸ System has a control and
diagnostic module that monitors and records current
system status and operational information.
If your vehicle is equipped with the 4 Wheel Steer
system it has the ability to steer the vehicle with all four
wheels.
Once the 4 Wheel Steer mode is selected, it is
recommended to leave the vehicle in this mode at all
times, and during all driving and weather conditions.
You can select this mode at any speed, however, if you
are turning the system will not engage until the turn
is complete.
The 4 Wheel Steer system is equipped with three
different driving modes:
·Two wheel steering (2)
·Four wheel steering (4)
·Four wheel steering with a trailer mode (_)The switch is located on the instrument panel.
2:In this mode the vehicle will operate like any other
vehicle with two wheel steering. If you want to use
2 wheel steering and your vehicle is not in this mode,
press the button until the 2 indicator, located to the right
of the 4 Wheel Steer button, lights up. If the 2 indicator
is ¯ashing you will have to center the steering wheel
by turning it to the left or right.
Your vehicle will return to 2 (two wheel steering) when
the transmission is shifted into NEUTRAL, for
example when entering a car wash.
4-12

_(4 Wheel Steer tow mode):When towing a
trailer the 4 wheel steer tow mode provides enhanced
stability allowing the trailer to follow the path of the
tow vehicle more closely, especially during lane
changes.
In this mode the system operates much like the 4 mode,
but is enhanced for trailer towing. It is recommended
for all types and weights of trailers.
To engage the 4 wheel steer tow mode, press the 4
Wheel Steer button until the 4 and tow indicators light up
on the instrument panel. If the tow indicator is ¯ashing
you will have to center the steering wheel by turning it to
the left or right. While in the 4 wheel steer tow mode,
it is possible the steering wheel may be slightly off
center. For more information, see
Towing a Trailer on
page 4-58.
Car Washes for
QUADRASTEERŸ Equipped Vehicles
Notice:Because your vehicle has a wider rear track
a small number of older car washes may be too
narrow for your vehicle. Conveyor systems on some
automatic car washes may damage your vehicle.
Only use conveyor system car washes with 13-inch
(33 cm) wide conveyor rails and/or stationary
washes with at least 82 inches (208 cm) between the
rails. Before using the car wash check with the
manager.
4-14

Tow/Haul Mode
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. The purpose of the
Tow/Haul mode is to:
·Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.
·Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
·Improve control of vehicle speed while requiring
less throttle pedal activity when pulling a heavy
trailer or a large or heavy load.
Your vehicle may be equipped with a switch at the end
of the shift lever which when pressed enables
Tow/Haul. When the switch is pressed, a light on the
instrument panel will illuminate to indicate that Tow/Haul
has been selected. Tow/Haul may be turned off by
pressing the switch again, at which time the indicator
light on the instrument panel will turn off. The vehicle will
automatically turn off Tow/Haul every time it is started.Tow/Haul is designed to be most effective when
the vehicle and trailer combined weight is at least
75 percent of the vehicle's Gross Combined Weight
Rating (GCWR). See Weight of the Trailer later in this
section. Tow/haul is most useful under the following
driving conditions:
·When pulling a heavy trailer or a large or heavy
load through rolling terrain.
·When pulling a heavy trailer or a large or heavy
load in stop and go traffic.
·When pulling a heavy trailer or a large or heavy
load in busy parking lots where improved low
speed control of the vehicle is desired.
Operating the vehicle in Tow/Haul when lightly loaded
or with no trailer at all will not cause damage. However,
there is no bene®t to the selection of Tow/Haul when
the vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/Haul is recommended only when pulling a heavy
trailer or a large or heavy load.
4-60

Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You'll need more passing distance up ahead when
you're towing a trailer. And, because you're a good deal
longer, you'll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Your vehicle is equipped with four-wheel steering and if
you use it while backing your trailer the same rules
apply. However, with four-wheel steering your rig will
respond more quickly and it may take additional practice
to get used to backing up with four-wheel steering.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you're turning with a trailer, make wider turns
than normal. Do this so your trailer won't strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will ¯ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ¯ash, telling other drivers
you're about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ¯ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It's
important to check occasionally to be sure the trailer
bulbs are still working.
4-66

Instrument Panel Jumper Wiring Harness
{CAUTION:
Be sure to use only the correct trailer brake
harness, the one intended for use on your
vehicle. If you use some other trailer brake
harness, even if it seems to ®t, your trailer
brakes may not work at all. You could have a
crash in which you or others could be injured.
Use only the trailer brake harness intended for
your vehicle. If it is no longer available to you,
be sure to get a proper replacement from your
dealer.This harness is included with your vehicle as part of the
heavy-duty trailer wiring package.
This harness is for an electric brake controller and
includes a trailer battery feed fuse. It should be installed
by your dealer or a quali®ed service center.
4-70

Engine Overheating
You will ®nd a coolant temperature gage on your
vehicle's instrument panel. SeeEngine Coolant
Temperature Gage on page 3-38. In addition, you will
®nd an ENGINE OVERHEATED, and a REDUCED
ENGINE POWER message in the DIC on the instrument
panel. See
Driver Information Center (DIC) on
page 3-46.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ®ring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil and
reset the oil life system. See
Engine Oil on
page 5-11.
5-25

Here are some cleaning tips:
·Always read the instructions on the cleaner label.
·Clean up stains as soon as you can ± before
they set.
·Carefully scrape off any excess stain.
·Use a clean cloth or sponge, and change to a clean
area often. A soft brush may be used if stains are
stubborn.
·If a ring forms on fabric after spot cleaning, clean
the entire area immediately or it will set.
Cleaning Vinyl
Use warm water and a clean cloth.
·Rub with a clean, damp cloth to remove dirt. You
may have to do this more than once.
·Things like tar, asphalt and shoe polish will stain if
you don't get them off quickly. Use a clean cloth
and vinyl cleaner. See your dealer for this product.
Cleaning Leather
Use a soft cloth with lukewarm water and a mild soap or
saddle soap and wipe dry with a soft cloth. Then, let
the leather dry naturally. Do not use heat to dry.
·For stubborn stains, use a leather cleaner.
·Neveruse oils, varnishes, solvent-based or abrasive
cleaners, furniture polish or shoe polish on leather.
·Soiled or stained leather should be cleaned
immediately. If dirt is allowed to work into the ®nish,
it can harm the leather.
Cleaning the Top of the Instrument
Panel
Use only mild soap and water to clean the top surfaces
of the instrument panel. Sprays containing silicones
or waxes may cause annoying re¯ections in the
windshield and even make it difficult to see through the
windshield under certain conditions.
5-97