
Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
............................................... 1-9
Safety Belts
.............................................1-11
Child Restraints
.......................................1-33
Airbag System
.........................................1-66
Restraint System Check
............................1-82
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-8
Windows
.................................................2-16
Theft-Deterrent Systems
............................2-19
Starting and Operating Your Vehicle
...........2-21
Mirrors
....................................................2-55
OnStar
®System
......................................2-64
HomeLink®Transmitter
.............................2-66
Storage Areas
.........................................2-70
Sunroof
..................................................2-73
Vehicle Personalization
.............................2-74
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-21
Warning Lights, Gages, and Indicators
........3-31
Driver Information Center (DIC)
..................3-50
Audio System(s)
.......................................3-69Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
........ 4-2
Towing
...................................................4-62
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-4
Fuel
......................................................... 5-6
Checking Things Under the Hood
...............5-12
Rear Axle
...............................................5-58
Four-Wheel Drive
.....................................5-58
Front Axle
...............................................5-60
Noise Control System
...............................5-61
Bulb Replacement
....................................5-62
Windshield Wiper Blade Replacement
.........5-72
Tires
......................................................5-72
Appearance Care
...................................5-112
Vehicle Identi cation
...............................5-120
Electrical System
....................................5-121
Capacities and Speci cations
...................5-130
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 Owner ManualM

The following situations can cause the transmission to
operate at higher temperatures:
Towing a trailer
Hot outside air temperatures
Vehicle overloading
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.
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.
3-44

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.
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. See “OIL PRESSURE LOW” underDIC
Warnings and Messages on page 3-54andEngine Oil
(Gasoline Engine) on page 5-20.
{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
3-47

Fuel Used:Press the fuel information button until
FUEL USED appears on the display. This mode shows
the number of gallons or liters of fuel used since the
last reset of this menu item. To reset the fuel used
information, press and hold the select button for
one second while FUEL USED is displayed.
Average Fuel Economy:Press the fuel information
button until AVG ECON appears on the display.
This mode shows how many miles per gallon (MPG) or
liters per 100 kilometers (L/100 km) your vehicle is
getting based on current and past driving conditions.
Press and hold the select button for one second while
AVG ECON is displayed to reset the average fuel
economy. Average fuel economy will then be calculated
starting from that point. If the average fuel economy is not
reset, it will be continually updated each time you drive.
Engine Oil Life System:Press the fuel information
button until ENGINE OIL LIFE appears on the display.
The engine oil life system shows an estimate of the oil’s
remaining useful life. It will show 100% when the
system is reset after an oil change. It will alert you to
change your oil on a schedule consistent with your
driving conditions.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 (Gasoline Engine) on page 5-23for 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 (Gasoline Engine) on page 5-20andScheduled
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 3-63for 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.
3-53