2005 GMC SIERRA DENALI service indicator

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

In many crashes severe enough to inate the airbag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur from the
right front passenger airbag.
Airbags are designed to inate only once. After they
inate, you will need some new parts for your airbag
system. If you do not get them, the airbag system will
not be there to help protect you in another crash. A
new system will include airbag modules and possibly
other parts. The service manual for your vehicle
covers the need to replace other parts.
Your vehicle is equipped with a crash sensing and
diagnostic module which records information after a
crash. SeeVehicle Data Collection and Event Data
Recorders on page 7-9.
Let only qualied technicians work on your airbag
system. Improper service can mean that an airbag
system will not work properly. See your dealer for
service.
Notice:If you damage the covering for the driver’s
or the right front passenger’s airbag, the bag
may not work properly. You may have to replace the
airbag module in the steering wheel or both the
airbag module and the instrument panel for the right
front passenger’s airbag. Do not open or break
the airbag coverings.
Passenger Sensing System
Your vehicle has a passenger sensing system. The
passenger airbag status indicator will be visible when
you turn your ignition key to START or RUN. The words
ON and OFF or the symbol for on and off, will be
visible on the rearview mirror during the system check.
When the system check is complete, either the word
ON or the word OFF, or the symbol for on or the symbol
for off will be visible. SeePassenger Airbag Status
Indicator on page 3-29.
Passenger Airbag Status Indicator – United States
Passenger Airbag Status Indicator – Canada
1-55

If a person of adult-size is sitting in the right front
passenger’s seat, but the off indicator is lit, it could be
because that person is not sitting properly in the seat. If
this happens, turn the vehicle off and ask the person to
place the seatback in the fully upright position, then sit
upright in the seat, centered on the seat cushion, with the
person’s legs comfortably extended. Restart the vehicle
and have the person remain in this position for about
two minutes. This will allow the system to detect that
person and then enable the passenger’s airbag.
{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
airbag system. If this ever happens, have the
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the frontal airbag. SeeAirbag Readiness
Light on page 3-29for more on this, including
important safety information.
1-58

Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol. The
system checks the airbag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the airbag
sensors, the airbag modules, the passenger sensing
system (if equipped), the wiring and the crash sensing
and diagnostic module. For more information on the
airbag system, seeAirbag System on page 1-48.
This light will come on
when you start your
vehicle, and it will ash for
a few seconds. This
means the system is
ready.
If the airbag readiness light stays on after you start the
vehicle or comes on when you are driving, your
airbag system may not work properly. Have your vehicle
serviced right away.
Passenger Airbag Status Indicator
Your vehicle has the passenger sensing system. Your
rearview mirror has a passenger airbag status indicator.
When the ignition key is turned to RUN or START, the
passenger airbag status indicator will light ON and
OFF, or the symbol for on and off, for several seconds
as a system check. Then, after several more seconds,
the status indicator will light either ON or OFF, or either
the on or off symbol to let you know the status of the
right front passenger’s frontal airbag.
Passenger Airbag Status Indicator – United States
Passenger Airbag Status Indicator – Canada
3-29

If the word ON or the on symbol is lit on the passenger
airbag status indicator, it means that the right front
passenger’s frontal airbag is enabled (may inate).
{CAUTION:
If the on indicator comes on when you have a
rear-facing child restraint installed in the right
front passenger’s seat, it means that the
passenger sensing system has not turned off
the passenger’s frontal airbag. A child in a
rear-facing child restraint can be seriously
injured or killed if the right front passenger’s
airbag inates. This is because the back of the
rear-facing child restraint would be very close
to the inating airbag. Do not use a rear-facing
child restraint in the right front passenger’s
seat unless the airbag has been turned off.
If the word OFF or the off symbol is lit on the airbag
status indicator, it means that the passenger sensing
system has turned off the right front passenger’s frontal
airbag. SeePassenger Sensing System on page 1-55
for more on this, including important safety information.If, after several seconds, all status indicator lights
remain on, or if there are no lights at all, there may be a
problem with the lights or the passenger sensing
system. See your dealer for service.
{CAUTION:
If the off indicator and the airbag readiness
light ever come on together, it means that
something may be wrong with the airbag
system. If this ever happens, have the vehicle
serviced promptly, because an adult-size
person sitting in the right front passenger seat
may not have the protection of the frontal
airbag. SeeAirbag Readiness Light on
page 3-29.
3-30

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

SERVICE BRAKE SYSTEM
If there is a problem with the brake system, this
message will be displayed 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 brake
system needs service. See your GM dealer.
SERVICE CHARGING SYSTEM
On some vehicles, if there is a problem with the battery
charging system, this message will appear on the
DIC. Under certain conditions, the battery warning light
may also turn on in the instrument panel cluster.
SeeBattery Warning Light on page 3-31. The battery
will not be charging at an optimal rate and the vehicle
will lose the ability to enter the fuel economy mode. The
vehicle is safe to drive, however you should have the
electrical system checked by your GM dealer. Pressing
any of the four DIC buttons, if equipped, will
acknowledge the message and clear it from the DIC
display. If your vehicle is not equipped with the four DIC
buttons, pressing the trip odometer reset stem will
acknowledge the message and clear it from the DIC
display.
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. See your GM dealer.
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. SeeMalfunction Indicator
Lamp on page 3-36. Reinstall the fuel cap fully. See
Filling Your Tank on page 5-7. 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 trips with the cap properly installed should turn
the light and message off.
3-52

The cut tape detection feature of the cassette tape
player may identify the cleaning cassette as a damaged
tape, in error. 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 AUX button for ve
seconds. The tape symbol on the display will
ash for two 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 ve seconds to reset the CLN indicator.
The radio will display --- or CLEANED 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.
Care of Your CDs
Handle CDs carefully. Store them in their original cases
or other protective cases and away from direct
sunlight and dust. If the surface of a CD is soiled,
dampen a clean, soft cloth in a mild, neutral detergent
solution and clean it, wiping from the center to the edge.
Be sure never to touch the side without writing when
handling CDs. Pick up CDs by grasping the outer edges
or the edge of the hole and the outer edge.
Care of Your CD Player
The use of CD lens cleaners for CD players is not
advised, due to the risk of contaminating the lens of the
CD optics with lubricants internal to the CD mechanism.
3-93