2005 GMC SIERRA DENALI service

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

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

Your vehicle has one
double-sided key for the
ignition and all door
locks as well as the spare
tire hoist lock, if equipped.
If you ever lose your keys, your dealer will be able to
assist you with obtaining replacements.
Notice:If you ever lock your keys in your vehicle,
you may have to damage the vehicle to get in.
Be sure you have spare keys.
If you ever do get locked out of your vehicle, call the
GM Roadside Assistance Center. SeeRoadside
Assistance Program on page 7-5. If your vehicle is
equipped with the OnStar
®system with an active
subscription and you lock your keys inside the vehicle,
OnStar
®may be able to send a command to unlock
your vehicle. SeeOnStar®System on page 2-34
for more information.
Remote Keyless Entry System
Your keyless entry system operates on a radio
frequency subject to Federal Communications
Commission (FCC) Rules and with Industry Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device may not cause interference, and
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
This device complies with RSS-210 of Industry Canada.
Operation is subject to the following two conditions:
1. This device may not cause interference, and
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
2-3

At times you may notice a decrease in range. This is
normal for any remote keyless entry system. If the
transmitter does not work or if you have to stand closer
to your vehicle for the transmitter to work, try this:
Check the distance. You may be too far from your
vehicle. You may need to stand closer during
rainy or snowy weather.
Check the location. Other vehicles or objects may
be blocking the signal. Take a few steps to the
left or right, hold the transmitter higher, and
try again.
Check to determine if battery replacement is
necessary. See “Battery Replacement” under
Remote Keyless Entry System Operation on
page 2-4.
If you are still having trouble, see your dealer or a
qualied technician for service.
Remote Keyless Entry System
Operation
You can lock and unlock your doors from about
3 feet (1 m) up to 100 feet (30 m) away using the remote
keyless entry transmitter supplied with your vehicle.
K(Unlock):Press this
button once to unlock the
driver’s door. The
interior lamps will come
on. Pressing unlock again
within three seconds
will cause the remaining
doors to unlock.
You can choose different feedback options for each
press of the unlock button. See “Lock Feedback” and
“Unlock Feedback” underDIC Vehicle Customization on
page 3-54for more information.
2-4

To replace the battery in the keyless entry transmitter,
do the following:
1. Insert a thin object, such as a coin, in the slot
between the covers of the transmitter housing
near the key ring hole. Remove the bottom
by twisting the coin.
2. Remove and replace the battery with a
three-volt CR2032 or equivalent battery, positive (+)
side up.3. Align the covers and snap them together.
4. Resynchronize the transmitter. See
“Resynchronization” following this information.
5. Check the operation of the transmitter.
Resynchronization
Resynchronization may be necessary due to the
security method used by this system. The transmitter
does not send the same signal twice to the receiver. The
receiver will not respond to a signal that has been
sent previously. This prevents anyone from recording
and playing back the signal from the transmitter.
To resynchronize your transmitter, stand close to your
vehicle and press and hold the lock and unlock
buttons on the transmitter at the same time for
15 seconds. The door locks should cycle to conrm
synchronization. If the locks do not cycle, see your
dealer for service.
2-6

Passlock®
Your vehicle is equipped with the
Passlock®theft-deterrent system.
Passlock
®is a passive theft-deterrent system.
Passlock®enables fuel if the ignition lock cylinder is
turned with a valid key. If a correct key is not used or the
ignition lock cylinder is tampered with, fuel is disabled.
If the engine stalls and the security light ashes,
wait until the light stops ashing before trying to restart
the engine. Remember to release the key from
START as soon as the engine starts.
If the engine is running and the security light comes on,
you will be able to restart the engine if you turn the
engine off. However, your Passlock
®system is
not working properly and must be serviced by your
dealer. Your vehicle is not protected by Passlock
®at this
time. You may also want to check the fuse. See
Fuses and Circuit Breakers on page 5-102. See your
dealer for service.
In an emergency, call the GM Roadside Assistance
Center. SeeRoadside Assistance Program on page 7-5.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
break-in. But it will perform better in the long run if
you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less for
the rst 500 miles (805 km).
Do not drive at any one speed — fast or
slow — for the rst 500 miles (805 km). Do not
make full-throttle starts.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time your new brake
linings are not yet broken in. Hard stops with new
linings can mean premature wear and earlier
replacement. Follow this breaking-in guideline
every time you get new brake linings.
Do not tow a trailer during break-in. SeeTowing a
Trailer on page 4-52for more information.
2-16