Marker Lamps
If your vehicle has this feature, you can manually blink
the marker and clearance lamps.
The marker lamp defeat
switch is located in the
instrument panel
switchbank.
Press and hold the bottom of the switch to turn off the
marker and clearance lamps. When you release
the switch, the marker and clearance lamps will come
back on.
Instrument Panel Brightness
This feature controls the brightness of the instrument
panel lights.
The thumbwheel for this feature is located to the right of
the exterior lamp control.
Turn the thumbwheel up to brighten the lights. When
the thumbwheel is moved to the first position, the radio
display and transmission selection display will go to
full intensity. The instrument panel cluster will also be
dimly lit. Moving the thumbwheel up to the next position
will activate the interior dome lamps.
Dome Lamps
The dome lamps will come on when you open a door.
You can also turn the dome lamps on by moving
the thumbwheel, located to the right of the exterior lamp
control, all the way up to the second position. In this
position, the dome lamps will remain on whether a door
is open or closed.
You can use the dome override button to set the dome
lamps to automatically come on when a door is
open, or to remain off.
3-16
Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour (km/h).
Your odometer shows how far your vehicle has
been driven, in either miles (used in the United States)
or kilometers (used in Canada).
Trip Odometer
The trip odometer can tell you how far your vehicle
has been driven since you last set the trip odometer
to zero.
While the engine is running, press the reset button,
located to the right of the trip odometer, to toggle
between the trip odometer and the regular odometer.
Holding the reset button for two seconds while the
engine is running and the trip odometer is displayed, will
reset it.
To display the odometer reading with the ignition off,
press the reset button.
The hourmeter gage is accessed through the trip
odometer, for more information seeHourmeter Gage on
page 3-44.
Tachometer
This gage shows the safe operating range for the
engine speed in revolutions per minute (rpm).
Engine Speed Limiter
All engines have electronic engine speed limiting. The
engine limited speeds range between
2,900 and 4,400 rpm depending on engine option
content.7.2L Caterpillar
®
Diesel Engine and
7.8L DURAMAX®
Diesel Engines
Gasoline and
6.6L DURAMAX®
Diesel Engines
3-26
Service Transmission Warning Light
If your vehicle has an Allison automatic transmission,
certain transmission malfunctions will turn this light on.
This light is located with
the auxiliary warning lights
in the center of the
instrument panel.
If this light comes on while you are driving, do not use
the transmission shift control or you may lose forward
gears. The computer for the transmission senses
a problem and chooses a gear to stay in so that you
can drive the vehicle in that gear. You may not be able
to drive as fast or back up when this light is on.
Notice:If you continue driving your vehicle after
the transmission warning light comes on, you could
damage the transmission. While this light is on,
the transmission cannot operate in all gears. If you
attempt to shift gears, the vehicle may not
continue to move. Do not attempt to shift gears
while the transmission warning light is on. Instead,
drive directly to a GM dealer for service. If you
cannot drive to a dealer immediately, have the
vehicle towed.
Range Inhibit Warning Indicator
If your vehicle has an Allison
1000/2000/2200/2400/2500 series automatic
transmission, a lighted bar under the current gear
selected will flash.
If your vehicle has an Allison 3000/3500 series automatic
transmission, the current gear selected on the pushbutton
display will flash.
The flashing bar or gear selection indicates that
transmission range shifts may not occur.
For detailed information on shift inhibit limitations, see
the Allison Automatic Transmission Operator’s Manual in
your vehicle for further information.
Brake System Warning Light
Your vehicle has either hydraulic or air brakes. Each
system has different warning lights.
3-31
Air Pressure Gage
If your vehicle has air
brakes, the air pressure
gage is located above the
switchbank in the center
of the instrument panel.
This gage shows the air pressure for both your front
and rear brake systems.
If the needle on the gage indicates that the air pressure
is below 60 to 75 psi (415 to 517 kPa), the low air
warning light will come on. An alarm will also sound if
this happens.
The top pointer shows the pressure available for the
front system, while the bottom pointer shows pressure
for the rear. There should be no more than 4 psi
(28 kPa) difference showing between the systems.
Don’t drive until both pointers are showing at least
120 psi (827 kPa), so you’ll have enough air if you need
to apply your brakes.
Hourmeter Gage
To access the engine hourmeter gage, press the trip
odometer button three times.
The instrument panel cluster displays the accumulated
engine run time hours using the reconfigurable
odometer display. The engine run time hours displays
only when the ignition is in the LOCK or ACCESSORY
position and the trip reset button is pressed for about
four seconds. The value of the accumulated hours does
not change when the battery is disconnected.
The hourmeter resets to 0.0 when 10,000 hours are
accumulated. The instrument panel cluster begins to
reaccumulate the engine run time hours from 0.0 hours.
Audio System(s)
Notice:Before adding any sound equipment to
your vehicle, such as an audio system, CD player,
CB radio, mobile telephone, or two-way radio, make
sure that it can be added by checking with your
dealer. Also, check federal rules covering mobile
radio and telephone units. If sound equipment can
be added, it is 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.
3-44
Notice:The chime signals related to seat belts,
parking brake, and other functions of your vehicle
operate through the GM radio/entertainment system.
If that equipment is replaced or additional
equipment is added to your vehicle, the chimes may
not work. Make sure that replacement or additional
equipment is compatible with your vehicle before
installing it.
Figure out which audio system is in your vehicle, find
out what your audio system can do, and how to operate
all of its controls.
Setting the Time
Press and hold the HR (down) or MIN (up) arrow for
two seconds. Then press HR until the correct hour
appears on the display. Press and hold MIN until the
correct minute appears on the display. The time can be
set with the ignition on or off.
AM-FM Radio
Playing the Radio
PWR (Power):Press this knob to turn the system on
and off.
VOL (Volume):Turn this knob to increase or to
decrease the volume.
RCL (Recall):Press this knob to switch the display
between the radio station frequency, band, and the
time. When the ignition is off, press this knob to display
the time.
3-45
Finding a Station
AM FM:Press this button to switch between FM1, FM2,
or AM. The display will show the selection.
TUNE:Turn this knob to select radio stations.
oSEEKp:Press the right or the left arrow to go to
the next or to the previous station and stay there.
To scan stations, press and hold either SEEK arrow for
two seconds until you hear a beep. The radio will go
to a station, play for a few seconds, then go on to
the next station. Press either SEEK arrow again to stop
scanning.
To scan preset stations, press and hold either SEEK
arrow for more than four seconds until you hear
two beeps. The radio will go to the first preset station
stored on the pushbuttons, play for a few seconds, then
go on to the next preset station. Press either SEEK
arrow again to stop scanning presets.
The radio will only seek and scan stations with a strong
signal that are in the selected band.
Setting Preset Stations
Up to 18 stations (six FM1, six FM2, and six AM) can be
programmed on the six numbered pushbuttons, by
performing the following steps:
1. Turn the radio on.
2. Press AM FM to select FM1, FM2, or AM.
3. Tune in the desired station.
4. Press and hold one of the six numbered
pushbuttons until you hear a beep. Whenever that
numbered pushbutton is pressed, the station
that was set will return.
5. Repeat the steps for each pushbutton.
Setting the Tone (Bass/Treble)
AUDIO:To adjust bass or treble, press and release
AUDIO until BAS or TRE appears on the display. Then
press and hold the up or the down arrow to increase
or to decrease. If a station is weak or noisy, decrease
the treble.
To adjust bass or treble to the middle position, select
BAS or TRE. Then press and hold AUDIO for more than
two seconds until you hear a beep. B and a zero or
T and a zero will appear on the display.
3-46
To adjust both tone controls and both speaker controls
to the middle position, first end out of audio mode
by pressing another button, causing the radio to perform
that function or by waiting five seconds for the display
to return to time of day. Then press and hold AUDIO for
more than two seconds until you hear a beep. CEN
will appear on the display.
Adjusting the Speakers (Balance/Fade)
AUDIO:To adjust the balance between the right
and the left speakers, press and release AUDIO until
BAL appears on the display. Then press and hold the up
or the down arrow to move the sound toward the right
or the left speakers.
To adjust the fade between the front and the rear
speakers, press and release AUDIO until FAD appears
on the display. Then press and hold the up or the
down arrow to move the sound toward the front or the
rear speakers.
To adjust balance or fade to the middle position, select
BAL or FAD. Then press and hold AUDIO for more
than two seconds until you hear a beep. L (balance) and
a zero or F and a zero will appear on the display.To adjust both tone controls and both speaker controls
to the middle position, first end out of audio mode
by pressing another button, causing the radio to perform
that function or by waiting five seconds for the display
to return to time of day. Then press and hold AUDIO for
more than two seconds until you hear a beep. CEN
will appear on the display.
Fade may not be available if the vehicle is a regular
cab model.Radio Messages
CAL (Calibrated):The audio system has been
calibrated for your vehicle from the factory. If CAL
appears on the display it means that the radio has not
been configured properly for your vehicle and must
be returned to your GM dealer for service.
LOC (Locked):This message is displayed when the
THEFTLOCK
®system has locked up. Take the vehicle
to your GM dealer for service.
If any error occurs repeatedly or if an error cannot be
corrected, contact your GM dealer.
3-47
Radio with Cassette
Playing the Radio
PWR (Power):Press this knob to turn the system on
and off.
VOL (Volume):Turn this knob to increase or to
decrease the volume.
RCL (Recall):Press this knob to switch the display
between the radio station frequency and the time. When
the ignition is off, press this knob to display the time.
Finding a Station
AM FM:Press this button to switch between FM1, FM2,
and AM. The display will show the selection.
TUNE:Turn this knob to select radio stations.
oSEEKp:Press the right or the left arrow to go to
the next or to the previous station and stay there.
To scan stations, press and hold one of the SEEK
arrows for two seconds until you hear a beep. The radio
will go to a station, play for a few seconds and flash
the station frequency, then go on to the next station.
Press one of the SEEK arrows again to stop scanning.
To scan preset stations, press and hold one of the
SEEK arrows for more than four seconds until you hear
two beeps. The radio will go to the first preset station
stored on the pushbuttons, play for a few seconds
and flash the station frequency, then go on to the next
preset station. Press one of the SEEK arrows again
to stop scanning presets.
The radio will only seek and scan stations with a strong
signal that are in the selected band.
3-48