Reduced Engine Power Light
If the check engine and
reduced engine power
lights are on, the throttle
may be disabled, and
a noticeable change in the
vehicle’s performance
may occur.
If the reduced engine power light is on, but there is no
change in performance, proceed to your destination.
The performance may be reduced the next time
the vehicle is driven. The vehicle may be driven at a
slower speed while the reduced engine power light is on,
but acceleration and speed may be limited.
Anytime the check engine light stays on, the vehicle
should be taken to an authorized GM dealer as soon as
possible for service.
Highbeam On Light
This light will come on
when the high-beam
headlamps are in use.
SeeHeadlamp High/Low-Beam Changer on page 3-8.
Daytime Running Lamps (DRL)
Indicator Light
This light is located on the
instrument panel cluster. It
goes on whenever the
Daytime Running Lamps
are on.
SeeDaytime Running Lamps (DRL) on page 3-15for
more information.
When it begins to get dark, the DRL indicator light is a
reminder to turn on your headlamps.
3-41
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 Messages
CAL (Calibration):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.
Playing a Cassette Tape
The tape player is built to work best with tapes that are
up to 30 to 45 minutes long on each side. Tapes
longer than that are so thin they may not work well in
this player. The longer side with the tape visible should
face to the right. If you hear nothing or hear a garbled
sound, the tape may not be in squarely. Press the eject
button to remove the tape and start over.
If the ignition and the radio are off, press the eject
button or the RCL knob to insert and to begin play of a
tape. If the ignition is on and the radio is off, the
tape can be inserted and will begin playing. CAS will
appear on the display when a tape is inserted.While the tape is playing, use the VOL, AUDIO, and
SEEK controls just as you do for the radio. The radio will
display UP if the top side of the tape is playing.
DN (Down) will appear if the bottom side is playing. The
tape player will play the other side of the tape when it
reaches the end.
Cassette tape adapter kits for portable CD players will
work in the cassette tape player. See “CD Adapter Kits”
later for more information.
The tape bias is set automatically when a metal or
chrome tape is inserted.
If an error appears on the display, see “Cassette Tape
Messages” later in this section.
1 PREV (Previous):The tape must have at least
three seconds of silence between each selection for
previous to work. Press this pushbutton to go to
the previous selection on the tape if the current selection
has been playing for less than three seconds. If
pressed when the current selection has been playing
from three to 13 seconds, it will go to the beginning
of the previous selection or the beginning of the current
selection, depending on the position on the tape. If
pressed when the current selection has been playing for
more than 13 seconds, it will go to the beginning of
the current selection. Pressing this pushbutton multiple
times will increase the number of selections to be
searched back, up to−9. Pressing the NEXT pushbutton
will cancel the selections.
3-50
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 the time of day. Then press and hold
the AUDIO button 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 (Calibration):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 cannot be corrected,
contact your GM dealer.
Playing a CD
Insert a CD partway into the slot, label side up. The
player will pull it in and the CD should begin playing. CD
will appear on the display. If you want to insert a CD
with the ignition off, first press the eject button or
the RCL knob.
If you insert a CD with the radio off and the ignition on,
it will start to play.
If the ignition or radio is turned off, with a CD in the
player, it will stay in the player. When the ignition
or radio is turned on, the CD will start playing where it
stopped, if it was the last selected audio source.
As each new track starts to play, the track number will
appear on the display.
The CD player can play the smaller 3 inch (8 cm) single
CDs with an adapter ring. Full-size CDs and the
smaller CDs are loaded in the same manner.
If playing a CD-R the sound quality may be reduced
due to CD-R quality, the method of recording, the quality
of the music that has been recorded, and the way the
CD-R has been handled. There may be an increase
in skipping, difficulty in finding tracks, and/or difficulty in
loading and ejecting. If these problems occur try a
known good CD.
3-55
Care of the Cassette Tape Player
A tape player that is not cleaned regularly can cause
reduced sound quality, ruined cassettes or a damaged
mechanism. Cassette tapes should be stored in their
cases away from contaminants, direct sunlight and
extreme heat. If they aren’t, they may not operate
properly or may cause failure of the tape player.
The tape player should be cleaned regularly after every
50 hours of use. The radio may display CLN to
indicate that the tape player has been used for 50 hours
without resetting the tape clean timer. If this message
appears on the display, the cassette tape player
needs to be cleaned. It will still play tapes, but it should
be cleaned as soon as possible to prevent damage
to the tapes and player. If there is a reduction in sound
quality, try a known good cassette to see if the tape
or the tape player is at fault. If this other cassette has no
improvement in sound quality, clean the tape player.
For best results, use a scrubbing action, non-abrasive
cleaning cassette with pads which scrub the tape
head as the hubs of the cleaner cassette turn. The
recommended cleaning cassette is available through
your dealer.The cut tape detection feature of the cassette tape
player may identify the cleaning cassette as a damaged
tape. To prevent the cleaning cassette from being
ejected, use the following steps:
1. Turn the ignition on.
2. Turn the radio off.
3. Press and hold the TAPE button for two seconds
until the radio produces one beep. CAS will flash
on the display for five seconds.
4. Insert the scrubbing action cleaning cassette.
5. Eject the cleaning cassette after the manufacturer’s
recommended cleaning time.
After the cleaning cassette is ejected, the cut tape
detection feature will be active again.
A non-scrubbing action, wet-type cleaner which uses a
cassette with a fabric belt to clean the tape head
can be used. This type of cleaning cassette will not
eject on its own. A non-scrubbing action cleaner may not
clean as thoroughly as the scrubbing type cleaner.
The use of a non-scrubbing action, dry-type cleaning
cassette is not recommended.
After the player is cleaned, press and hold the eject
button for three seconds to reset the CLN indicator. The
radio will display --- to show the indicator was reset.
Cassettes are subject to wear and the sound quality may
degrade over time. Always make sure the cassette
tape is in good condition before the tape player
is serviced.
3-58
Before changing lanes, check your mirrors. Then use
your turn signal.
Once you are moving on the freeway, make certain you
allow a reasonable following distance. Expect to
move slightly slower at night.
When you want to leave the freeway, move to the
proper lane well in advance. If you miss your exit, do
not, under any circumstances, stop and back up. Drive
on to the next exit.
The exit ramp can be curved, sometimes quite
sharply. The exit speed for cars — but not larger
vehicles — is usually posted. You should go
more slowly.
Reduce your speed according to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you may tend to think you are
going slower than you actually are.Highway Hypnosis
Is there actually such a condition as highway hypnosis?
Or is it just plain falling asleep at the wheel? Call it
highway hypnosis, lack of awareness, or whatever.
When you drive the vehicle for a long distance, there is
something about an easy stretch of road with the
same scenery, along with the hum of the tires on the
road, the drone of the engine, and the rush of the wind
against the vehicle that can make you sleepy. Do
not let it happen to you! If it does, your vehicle can leave
the road in less than a second, and you could crash
and be injured.
What can you do about highway hypnosis? First, be
aware that it can happen.
Then here are some tips:
•Make sure your vehicle is well ventilated, with a
comfortably cool interior.
•Keep your eyes moving. Scan the road ahead and
to the sides. Check your mirrors and your
instruments frequently.
•If you get sleepy, pull off the road into a rest,
service, or parking area and take a nap, get some
exercise, or both. For safety, treat drowsiness
on the highway as an emergency.
4-23
Towing
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your disabled vehicle towed. See
Roadside Assistance Program on page 7-5.
Releasing Air-Operated Parking Brakes
If your vehicle has air brakes, you could have a
special towing problem. If your vehicle has to be towed
because of a complete loss of air pressure from
both systems, the parking brakes will have automatically
engaged. The tow operator can release the brakes
manually by using the following steps. Then your vehicle
can be towed with all wheels or only the rear wheels
on the ground.
1. Block the wheels of the vehicle.2. Remove the release stud and nut from the side of
the brake chamber. Some chambers have studs
which are visible at all times.
4-35
Service............................................................5-3
Doing Your Own Service Work.........................5-4
Two Safety Cautions about Engine Fan
Breakage...................................................5-5
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
Additives.......................................................5-6
Diesel Engine Fuel.........................................5-7
What Fuel to Use...........................................5-8
Very Cold Weather Operation.........................5-10
Water in Fuel...............................................5-10
Running Out of Fuel.....................................5-15
Fuel Filter Replacement.................................5-16
Fuels in Foreign Countries.............................5-17
Filling the Tank............................................5-18
Filling a Portable Fuel Container.....................5-19
Checking Things Under the Hood....................5-20
Hood Latches...............................................5-20
Engine Oil (Caterpillar
®Diesel Engine).............5-22
Engine Oil (DURAMAX®Diesel)......................5-22
Engine Oil (Gasoline Engine)..........................5-26
Engine Oil Life System (Gasoline Engine)........5-29
Engine Oil Life System (DURAMAX
®Diesel).....5-31
Engine Oil Life System (Caterpillar®
Diesel Engine)..........................................5-32Engine Air Cleaner/Filter................................5-33
Automatic Transmission Fluid.........................5-34
Manual Transmission Fluid.............................5-35
Engine Coolant (Gas and
DURAMAX
®Engines).................................5-36
Engine Coolant (Caterpillar®Diesel Engines).....5-38
Coolant Surge Tank Pressure Cap..................5-38
Engine Overheating.......................................5-38
Cooling System (Gas and
DURAMAX
®Engines).................................5-40
Engine Fan Noise.........................................5-45
Power Steering Fluid.....................................5-45
Windshield Washer Fluid................................5-46
Brakes........................................................5-47
Battery........................................................5-55
Jump Starting...............................................5-56
Rear Axle.......................................................5-60
Rear Axle Shift Motor....................................5-62
Four-Wheel Drive............................................5-62
Front Axle......................................................5-63
Noise Control System.....................................5-64
Tampering with Noise Control System
Prohibited.................................................5-64
Bulb Replacement..........................................5-65
Windshield Wiper Blade Replacement..............5-65
Section 5 Service and Appearance Care
5-1