2005 GMC SIERRA DENALI maintenance

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
............................................... 1-6
Safety Belts
.............................................. 1-8
Child Restraints
.......................................1-27
Airbag System
.........................................1-48
Restraint System Check
............................1-61
Features and Controls..................................... 2-1
Keys
........................................................ 2-2
Doors and Locks
....................................... 2-7
Windows
.................................................2-12
Theft-Deterrent Systems
............................2-14
Starting and Operating Your Vehicle
...........2-16
Mirrors
....................................................2-29
OnStar
®System
......................................2-34
HomeLink®Transmitter
.............................2-36
Storage Areas
.........................................2-41
Sunroof
..................................................2-43
Vehicle Personalization
.............................2-44
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-20
Warning Lights, Gages, and Indicators
........3-26
Driver Information Center (DIC)
..................3-42Audio System(s)
.......................................3-60
Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-51
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-5
Checking Things Under the Hood
...............5-10
All-Wheel Drive
........................................5-46
Rear Axle
...............................................5-47
Front Axle
...............................................5-48
Bulb Replacement
....................................5-49
Windshield Wiper Blade Replacement
.........5-55
Tires
......................................................5-56
Appearance Care
.....................................5-92
Vehicle Identication
...............................5-101
Electrical System
....................................5-102
Capacities and Specications
...................5-112
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance and Information.............. 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-10
Index................................................................ 1
2005 GMC Sierra Denali Owner ManualM

Aftermarket equipment, such as seat covers, can affect
how well the passenger sensing system operates.
You may want to consider not using seat covers or other
aftermarket equipment if your vehicle has the passenger
sensing system. SeeAdding Equipment to Your
Airbag-Equipped Vehicle on page 1-60for more
information about modications that can affect how the
system operates.
{CAUTION:
Stowing of articles under the passenger’s seat
or between the passenger’s seat cushion and
seatback may interfere with the proper
operation of the passenger sensing system.
Servicing Your Airbag-Equipped
Vehicle
Airbags affect how your vehicle should be serviced.
There are parts of the airbag system in several places
around your vehicle. You do not want the system to
inate while someone is working on your vehicle. Your
dealer and the service manual have information
about servicing your vehicle and the airbag system. To
purchase a service manual, seeService Publications
Ordering Information on page 7-11.
{CAUTION:
For up to 10 seconds after the ignition key is
turned off and the battery is disconnected, an
airbag can still inate during improper service.
You can be injured if you are close to an
airbag when it inates. Avoid yellow
connectors. They are probably part of the
airbag system. Be sure to follow proper
service procedures, and make sure the person
performing work for you is qualied to do so.
The airbag system does not need regular maintenance.
1-59

Restraint System Check
Checking Your Restraint Systems
Now and then, 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.
Torn or frayed safety belts may not protect you in a
crash. They can rip apart under impact forces. If a belt
is torn or frayed, get a new one right away.
Also look for any opened or broken airbag covers, and
have them repaired or replaced. (The airbag system
does not need regular maintenance.)
Replacing Restraint System Parts
After a Crash
{CAUTION:
A crash can damage the restraint systems in
your vehicle. A damaged restraint system may
not properly protect the person using it,
resulting in serious injury or even death in a
crash. To help make sure your restraint
systems are working properly after a crash,
have them inspected and any necessary
replacements made as soon as possible.
1-61

SeeDriver Information Center (DIC) on page 3-42for
further information.
If the transmission uid reaches temperatures of
approximately 275°F (135°C) or greater, the Driver
Information Center will display a TRANS HOT IDLE
ENGINE warning message, and a chime will sound. Pull
the vehicle off the roadway when it is safe to do so.
Set the parking brake, place the transmission in
PARK (P) and allow the engine to idle until the
transmission temperature falls below 260°F (127°C).
If the transmission continues to operate above
265°F (130°C), contact your nearest dealer or the GM
Roadside Assistance Center. SeeRoadside Assistance
Program on page 7-5.
Notice:If you drive your vehicle with the
transmission temperature gage above normal
operating range, you can damage the transmission.
This could lead to costly repairs that would not
be covered by your warranty. Do not drive your
vehicle while the transmission temperature gage
reading is above normal. See your dealer for service.The following situations can cause the transmission to
operate at higher temperatures:
Towing a trailer
Hot outside air temperatures
Hauling a large or heavy load
Low transmission uid level
High transmission uid level
Restricted air ow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, seeScheduled Maintenance
on page 6-4for the proper transmission maintenance
intervals.
3-35

Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition, and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. The check engine light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls
may not work as well, your fuel economy may not
be as good, and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
3-36

Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. Poor fuel quality will
cause your engine not to run as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misring, hesitation
on acceleration, or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to x any
mechanical or electrical problems that may have
developed.Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the check
engine light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This may take several days
of routine driving. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your GM dealer can prepare the
vehicle for inspection.
3-38

Oil Pressure Gage
The oil pressure gage shows the engine oil pressure in
psi (pounds per square inch) when the engine is
running. Canadian vehicles indicate pressure in
kPa (kilopascals).
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.
A reading in the low pressure zone may be caused
by a dangerously low oil level or some other problem
causing low oil pressure. Check your oil as soon
as possible. SeeDIC Warnings and Messages on
page 3-45andEngine Oil on page 5-14.
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil. United States
Canada
3-39

Always reset the engine oil life system after an oil
change. To reset the engine oil life system, use the fuel
button to reach the ENGINE OIL LIFE screen and
then press and hold the select button for ve seconds
while ENGINE OIL LIFE is displayed. OIL LIFE
RESET will appear on the display for 10 seconds to let
you know the system is reset. SeeEngine Oil Life
System on page 5-17for more information.
In addition to the engine oil life system monitoring the
oil life, additional maintenance is recommended in
the Maintenance Schedule in this manual. SeeEngine
Oil on page 5-14andScheduled Maintenance on
page 6-4.
Customization Button
4
(Customization):Press the customization button to
access the VEHICLE SETTINGS menu and customize
the settings to your vehicle. SeeDIC Vehicle
Customization on page 3-54for more information.
Select Button
r
(Select):Press the select button to reset certain
DIC functions and set your customization settings.
For example, this button will reset the trip odometers
and scroll through the languages in which you can select
the DIC to display information.
DIC Warnings and Messages
Warning messages are displayed on the Driver
Information Center (DIC) to notify the driver that the
status of the vehicle has changed and that some action
may be needed by the driver to correct the condition.
If there is more than one message that needs to
be displayed, they will appear one after another. Some
messages may not require immediate action, but
you should press any of the four DIC buttons on the
steering wheel, if equipped, to acknowledge that
you received the messages and clear them from the
display. If your vehicle is not equipped with DIC buttons
on the steering wheel, press the trip odometer reset
stem located on the instrument panel cluster to
acknowledge messages and clear them from the display.
Some messages cannot be cleared from the display
because they are more urgent. These messages require
action before they can be removed from the DIC
display. You should take any messages that appear on
the display seriously and remember that clearing the
messages will only make the messages disappear, not
correct the problem. The following are the possible
messages that can be displayed and some information
about them.
3-45