2004 GMC SIERRA instrument panel

TRANS HOT IDLE ENGINE
(Allison TransmissionžOnly)
If the transmission ¯uid in the vehicle gets hot, this
message will appear on the DIC, and you will hear a
chime. The chime will stop when the transmission ¯uid
temperature is less that 265ÉF (129ÉC). Driving with
the transmission ¯uid temperature high can cause
damage to the vehicle. Stop the vehicle and let it idle to
allow the transmission to cool. This message will
clear when the ¯uid temperature reaches a safe level.
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.
TURN SIGNAL ON
If a turn signal is left on for 3/4 of a mile (1.2 km), this
message will appear on the display and you will
hear a chime. Move the turn signal/multifunction lever to
the off position. Press the select button to acknowledge
the message and clear it from the DIC display.
Audio System(s)
Notice:Before you add any sound equipment to
your vehicle ± like a tape player, CB radio, mobile
telephone or two-way radio ± be sure you can
add what you want. If you can, it's very important to
do it properly. Added sound equipment may
interfere with the operation of your vehicle's engine,
radio or other systems, and even damage them.
Your vehicle's systems may interfere with the
operation of sound equipment that has been added
improperly.
So, before adding sound equipment, check with
your dealer and be sure to check federal rules
covering mobile radio and telephone units.
Your audio system has been designed to operate easily
and to give years of listening pleasure. You will get
the most enjoyment out of it if you acquaint yourself with
it ®rst. Figure out which radio you have in your vehicle,
®nd out what your audio system can do and how to
operate all of its controls to be sure you're getting the
most out of the advanced engineering that went into it.
Your vehicle may have a feature called Retained
Accessory Power (RAP). With RAP, you can play your
audio system even after the ignition is turned off.
See ªRetained Accessory Power (RAP)º under
Ignition
Positions on page 2-22.
3-73

·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

The next time you start your vehicle, the TAS will not
automatically come on. You can restore the automatic
feature by repeating the same procedure. Whether
the TAS is set to come on automatically or not, you can
always turn the system on or off by pressing the TAS
on/off button.
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.
4-11

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 steer mode 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 when the transmission is
shifted into NEUTRAL (N), for example when entering a
car wash.
If you want to use tire chains, the vehicle needs to be in
2 wheel steer mode. For more information see
Tire
Chains on page 5-94.
4-14

To engage the 4 Wheel Steer tow mode, press the
button until the 4 and tow mode 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 4-70.
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.
4-16

Tow/Haul Mode
Tow/Haul is a feature on automatic transmission
equipped vehicles 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.
Automatic transmission equipped vehicles are provided
with a button at the end of the shift lever which when
pressed enables Tow/Haul. When the button 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 button 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% of
the vehicle's Gross Combined Weight Rating (GCWR).
See ªWeight of the Trailerº later in the 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.
4-72

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.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
If you have an automatic transmission, you can tow in
DRIVE (D). You may want to shift the transmission
to lower gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See
Tow/Haul Mode
Light on page 3-53.If you have a 5-speed manual transmission and you are
towing a trailer, it's better not to use FIFTH (5) gear.
Just drive in FOURTH (4) gear (or, as you need
to, a lower gear).
If you have a 6-speed manual transmission and you are
towing a trailer, it's better not to use SIXTH (6) gear.
Drive in FIFTH (5) gear (or, as you need to, a lower gear).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked, preferably on level ground, with
the automatic transmission in PARK (P) for a few
minutes before turning the engine off. For manual
transmissions, let the engine run while parked,
preferably on level ground, with the transmission out of
gear and the parking brake applied, for a few minutes
before turning the engine off. If you do get the overheat
warning, see
Engine Overheating on page 5-36.
4-93

If your vehicle is equipped with the ªHeavy-Duty
Trailering²option, please refer toHeavy-Duty Trailer
Wiring Package, earlier in this section.
When the camper-wiring harness is ordered without the
heavy-duty trailering package, an eight-wire harness
with a seven-pin connector and separate CHMSL
connector are located at the rear of the vehicle and are
tied to the vehicle's frame.
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.
4-98