2004 GMC SIERRA DENALI air suspension

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. Press the SELECT button
to acknowledge the message.
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 begin driving, the four wheel
steer system needs service. Press the SELECT button
to acknowledge the message and clear it from the
DIC display.
SERVICE AIR SUSPENSION
If a problem occurs with the suspension system, this
message will appear on the DIC. If this message
appears, stop as soon as possible and turn off thevehicle. 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. Press the SELECT
button to acknowledge the message.
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 to drive, the air suspension system
needs service.
TIGHTEN FUEL CAP
If the vehicle's fuel cap is not tightened properly this
message may appear along with the check engine light
on the instrument panel. See
Malfunction Indicator
Lamp on page 3-40. Reinstall the fuel cap fully. SeeFilling Your Tank on page 5-6. 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 tips with the cap properly installed should turn
the light and message off.
3-62

{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR. If you do, parts on your vehicle can
break, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
This will help you decide how much cargo and installed
equipment your truck can carry.
Using heavier suspension components to get added
durability might not change your weight ratings. Ask your
dealer to help you load your vehicle the right way.
If you put things inside your vehicle ± like suitcases,
tools, packages, or anything else ± they go as fast
as the vehicle goes. If you have to stop or turn quickly,
or if there is a crash, they'll keep going.
{CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn, or
in a crash.
·Put things in the cargo area of your
vehicle. Try to spread the weight evenly.
·Never stack heavier things, like suitcases,
inside the vehicle so that some of them
are above the tops of the seats.
·Do not leave an unsecured child restraint
in your vehicle.
·When you carry something inside the
vehicle, secure it whenever you can.
·Do not leave a seat folded down unless
you need to.
There's also important loading information for off-road
driving in this manual. See ªLoading Your Vehicle
for Off-Road Drivingª under
Operating Your
All-Wheel-Drive Vehicle Off Paved Roads on page 4-18.
4-53

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and ®lter. Reset oil life system. See
Engine Oil on
page 5-11.An Emission Control Service.··
Lubricate chassis components.
See footnote #.··
Visually check for any leaks or damage.
See footnote (j).··
Inspect engine air cleaner ®lter or change indicator (if equipped). If necessary,
replace ®lter. See
Engine Air Cleaner/Filter on page 5-16.An Emission Control
Service. See footnote ².··
Rotate tires and check in¯ation pressures and wear. See
Tires on page 5-59.··
Inspect brake system.
See footnote (a).··
Check engine coolant and windshield washer ¯uid levels and add ¯uid as
needed.··
Perform any needed additional services. See ªAdditional Required Servicesº in
this section.··
Inspect suspension and steering components.
See footnote (b).·
Inspect engine cooling system.
See footnote (c).·
Inspect wiper blades.
See footnote (d).·
Inspect restraint system components.
See footnote (e).·
Lubricate body components.
See footnote (f).·
Check transmission ¯uid level and add ¯uid as needed.·
6-5

Maintenance Footnotes
²The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle's useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
#Lubricate the front suspension, ball joints, steering
linkage, transmission shift linkage and parking
brake cable guides. Ball joints should not be lubricated
unless their temperature is 10ÉF (-12ÉC) or higher,
or they could be damaged.
(a)Visually inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, cha®ng, etc. Inspect
disc brake pads for wear and rotors for surface
condition. Inspect other brake parts, including calipers,
parking brake, etc.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose or missing parts,
signs of wear or lack of lubrication. Inspect power
steering lines and hoses for proper hook-up, binding,
leaks, cracks, cha®ng, etc. Visually check constant
velocity joints, rubber boots and axle seals for leaks.
(c)Visually inspect hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
®ttings and clamps; replace with genuine GM parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Visually inspect wiper blades for wear or cracking.
Replace blade inserts that appear worn or damaged
or that streak or miss areas of the windshield.
(e)Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced. Also look for any opened or broken air bag
coverings, and have them repaired or replaced. (The air
bag system does not need regular maintenance.)
(f)Lubricate all key lock cylinders, body door hinges,
hood latch assembly, secondary latch, pivots, spring
anchor, release pawl, tailgate hinges, tailgatelinkage,
tailgate handle pivot points, latch bolt, fuel door
hinge, locks and folding seat hardware. More frequent
lubrication may be required when exposed to a corrosive
environment. Applying silicone grease on weatherstrips
with a clean cloth will make them last longer, seal
better and not stick or squeak.
6-8

Reporting Safety Defects to the
Canadian Government
If you live in Canada, and you believe that your vehicle
has a safety defect, you should immediately notify
Transport Canada, in addition to notifying General
Motors of Canada Limited. You may write to:
Transport Canada
330 Sparks Street
Tower C
Ottawa, Ontario K1A 0N5
Reporting Safety Defects to General
Motors
In addition to notifying NHTSA (or Transport Canada) in
a situation like this, we certainly hope you'll notify us.
Please call us at 1-800-GMC-8782 (1-800-462-8782),
or write:
Pontiac-GMC Customer Assistance Center
P.O. Box 33172
Detroit, MI 48232-5172In Canada, please call us at 1-800-263-3777 (English)
or 1-800-263-7854 (French). Or, write:
General Motors of Canada Limited
Customer Communication Centre, 163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Service Publications Ordering
Information
Service Manuals
Service Manuals have the diagnosis and repair
information on engines, transmission, axle, suspension,
brakes, electrical, steering, body, etc.
RETAIL SELL PRICE: $120.00
Transmission, Transaxle, Transfer
Case Unit Repair Manual
This manual provides information on unit repair service
procedures, adjustments, and speci®cations for GM
transmissions, transaxles, and transfer cases.
RETAIL SELL PRICE: $50.00
7-11

Secondary Latch System.................................5-92
Securing a Child Restraint
Center Rear Seat Position............................1-54
Designed for the LATCH System...................1-46
Rear Outside Seat Position...........................1-51
Right Front Seat Position..............................1-56
Security While You Travel.................................. 7-6
Select Button.................................................3-57
Service........................................................... 5-3
Adding Equipment to the Outside of Your
Vehicle..................................................... 5-4
Doing Your Own Work................................... 5-3
Engine Soon Light.......................................3-40
Publications Ordering Information...................7-11
SERVICE 4 WHEEL STEER.............................3-62
SERVICE 4WD...............................................3-62
SERVICE AIR SUSPENSION...........................3-62
SERVICE AIRBAG..........................................3-60
SERVICE BRAKE BOOSTER...........................3-61
SERVICE BRAKE SYSTEM.............................3-61
Service Bulletins.............................................7-12
Service Manuals.............................................7-11
SERVICE RIDE CONTROL..............................3-62
Setting Preset PTYs (RDS Only).......................3-70
Setting Preset Stations....................................3-67
Setting the Time.............................................3-64
Setting the Tone (Bass/Treble)..........................3-68
Sheet Metal Damage.....................................5-101
Shifting Into Park (P).......................................2-26
Shifting Out of Park (P)...................................2-28Skidding........................................................4-17
Some Other Rainy Weather Tips.......................4-35
Spare Tire.....................................................5-95
Speci®cations, Capacities...............................5-114
Speedometer..................................................3-29
Stalling on an Incline.......................................4-29
Starting Your Engine.......................................2-19
Steering........................................................4-10
Steering in Emergencies..................................4-11
Steering Tips..................................................4-10
Steering Wheel Controls, Audio.........................3-85
Storage Areas
Center Console Storage Area........................2-42
Cupholder(s)...............................................2-42
Glove Box..................................................2-42
Storing a Flat or Spare Tire, Jack and Tools.......5-88
Stuck in Sand, Mud, Ice or Snow......................4-46
Sun Visors.....................................................2-15
Swing-Out Windows........................................2-15
T
Tachometer....................................................3-29
Tailgate.........................................................2-11
Tailgate Removal............................................2-12
Taillamps.......................................................5-56
Temperature and Compass Display....................2-31
Testing the Alarm............................................2-17
Theft-Deterrent, Radio.....................................3-85
13