2008 GMC ENVOY fuel cap

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
..............................................1-11
Safety Belts
.............................................1-13
Child Restraints
.......................................1-32
Airbag System
.........................................1-53
Restraint System Check
............................1-68
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-7
Windows
.................................................2-13
Theft-Deterrent Systems
............................2-16
Starting and Operating Your Vehicle
...........2-20
Mirrors
....................................................2-39
OnStar
®System
......................................2-48
Universal Home Remote System
................2-52
Storage Areas
.........................................2-57
Sunroof
..................................................2-60
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-21
Warning Lights, Gages, and Indicators
........3-30
Driver Information Center (DIC)
..................3-49
Audio System(s)
.......................................3-65Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-40
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-5
Checking Things Under the Hood
...............5-10
Rear Axle
...............................................5-46
Four-Wheel Drive
.....................................5-47
Front Axle
...............................................5-48
Headlamp Aiming
.....................................5-49
Bulb Replacement
....................................5-49
Windshield Wiper Blade Replacement
.........5-54
Tires
......................................................5-57
Appearance Care
...................................5-100
Vehicle Identication
...............................5-108
Electrical System
....................................5-109
Capacities and Specications
...................5-120
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance Information.................... 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-15
Vehicle Data Recording and Privacy
...........7-18
Index................................................................ 1
2008 GMC Envoy and Envoy Denali Owner ManualM

Security Light...............................................3-46
Cruise Control Light......................................3-46
Reduced Engine Power Light.........................3-46
Highbeam On Light.......................................3-47
Service Four-Wheel Drive Warning Light..........3-47
Check Gages Warning Light...........................3-47
Gate Ajar Light.............................................3-48
Fuel Gage...................................................3-48
Low Fuel Warning Light.................................3-49
Check Gas Cap Light....................................3-49
Driver Information Center (DIC).......................3-49
DIC Operation and Displays...........................3-50
DIC Warnings and Messages.........................3-53
DIC Vehicle Customization.............................3-58Audio System(s).............................................3-65
Setting the Clock..........................................3-66
Radio(s)......................................................3-66
Using an MP3..............................................3-82
XM Radio Messages.....................................3-86
Navigation/Radio System...............................3-87
Rear Seat Entertainment (RSE) System...........3-87
Rear Seat Audio (RSA)................................3-100
Theft-Deterrent Feature................................3-101
Audio Steering Wheel Controls......................3-101
Radio Reception.........................................3-102
Fixed Mast Antenna....................................3-103
XM™ Satellite Radio Antenna System............3-103
Chime Level Adjustment...............................3-103
Section 3 Instrument Panel
3-2

If the Light is Flashing
The following can prevent more serious damage to your
vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid steep uphill grades.
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stops ashing and remains on steady,
see “If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park the vehicle.
Turn the ignition off, wait at least 10 seconds, and restart
the engine. If the light remains on steady, see “If the
Light Is On Steady” following. If the light is still ashing,
follow the previous steps and see your dealer/retailer
for service as soon as possible.
If the Light Is On Steady
You might be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling the Tank on page 5-8. The diagnostic
system can determine if the fuel cap has been left off orimproperly installed. A loose or missing fuel cap allows
fuel to evaporate into the atmosphere. A few driving trips
with the cap properly installed should turn the light off.
Did you just drive through a deep puddle of water?
If so, your vehicle’s electrical system might be wet.
The condition is usually corrected when the electrical
system dries out. A few driving trips should turn the
light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-6. Poor fuel quality causes
the engine not to run as efficiently as designed. You
might 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 might 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/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that might have developed.
3-43

Gate Ajar Light
If this light comes on, the
liftgate or liftglass is not
completely shut.
Close the liftgate or liftglass. Never drive with the liftgate
or liftglass even partially open.
Fuel Gage
When the ignition is on, the fuel gage tells you about
how much fuel you have remaining.
Here are four things that some owners ask about.
None of these show a problem with your fuel gage:
At the gas station, the gas pump shuts off before the
gage reads full.
It takes a little more or less fuel to ll up than the
gage indicated. For example, the gage may have
indicated the tank was half full, but it actually took a
little more or less than half the tank’s capacity to
ll the tank.
The gage moves a little when you turn a corner or
speed up.
The gage doesn’t go back to empty when you turn
off the ignition.
United StatesCanada
3-48

Low Fuel Warning Light
The light next to the fuel gage will come on briey when
you are starting the engine.
This light comes on when the fuel tank is low on fuel.
To turn it off, add fuel to the fuel tank. SeeFuel on
page 5-5.
Check Gas Cap Light
If your vehicle has this
light, it will come on if your
gas cap is not securely
fastened.
SeeMalfunction Indicator Lamp on page 3-41for more
information.
Driver Information Center (DIC)
Your vehicle may have this feature. The Driver
Information Center (DIC) display is located on the
instrument panel cluster, below the speedometer.
If your vehicle has DIC buttons, they are located on
the steering wheel. The DIC can display information
such as the trip odometer, fuel economy, customization
features, and warning/status messages.
If your vehicle does not have DIC steering wheel
buttons, you will not have all of the features listed.
Scroll through the odometer and trip odometer by
pressing the trip odometer reset stem located on the
instrument panel cluster. Turn off, or acknowledge, DIC
messages by pressing the trip odometer reset stem.
SeeSpeedometer and Odometer on page 3-32for
information on features for vehicles without DIC buttons.
3-49

TIGHTEN FUEL CAP
This message may display and a chime may sound if
the vehicle’s fuel cap is not tightened properly. Fully
reinstall the fuel cap. SeeFilling the Tank on page 5-8.
The diagnostic system can determine if the fuel cap
has been left off or improperly installed. A loose
or missing fuel cap allows fuel to evaporate into the
atmosphere. This message remains on until it is
manually cleared from the DIC display. The DIC
message is also cancelled if the ignition is turned off.
The DIC message and the Service Engine Soon
light may come on again during a second trip if the
fuel cap is still not tightened properly. SeeMalfunction
Indicator Lamp on page 3-41for more information.
TRACTION CONTROL OFF
This message displays when you momentarily press
the StabiliTrak®button located on the transmission
shift handle. In this mode, stability control and the
brake-traction control are functional. Engine speed
management will be modied and the driven wheels
can spin more freely. For more details on this mode,
seeStabiliTrak
®System on page 4-6.
TURN SIGNAL ON
This message displays and a chime sounds if a turn
signal is left on for 3/4 of a mile (1.2 km). Move the turn
signal/multifunction lever to the off position.
DIC Vehicle Customization
Your vehicle may have customization capabilities that
allow you to program some features to one setting
based on your preference. All of the customizable
options listed may not be available on your vehicle.
Only the options available display on the Driver
Information Center (DIC).
The default settings for the customization features were
set when your vehicle left the factory, but may have
been changed from their default state since then.
To change feature preferences, make sure the ignition
is on and the vehicle is in PARK (P). To avoid excessive
drain on the battery, it is recommended that the
headlamps are turned off.
Press the customization button to scroll through the
available customizable options.
After pressing the customization button, VEHICLE
SETTINGS momentarily displays before going to a
customization option.
3-58

Your vehicle may have an electronically controlled
air suspension system that automatically keeps
your vehicle level as you load and unload
your vehicle. SeeElectronically Controlled Air
Suspension System on page 4-44for additional
information.
Certication/Tire Label
A vehicle specic Certication/Tire label is
found on the rear edge of the driver’s door.
The label shows the size of your vehicle’s original
tires and the ination pressures needed to
obtain the gross weight capacity of your vehicle.This is called Gross Vehicle Weight
Rating (GVWR). The GVWR includes the
weight of the vehicle, all occupants, fuel, cargo,
and trailer tongue weight, if pulling a trailer.
The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR). To nd
out the actual loads on your front and rear axles,
you need to go to a weigh station and weigh your
vehicle. Your dealer can help you with this. Be sure
to spread out your load equally on both sides of the
centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, you should
spread it out.
Similar appearing vehicles may have different
GVWRs and capacity weights. Please note your
vehicle’s Certication/Tire label or consult your
dealer for additional details.
4-38

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-6
Gasoline Specications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-7
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Oil Life System..................................5-19
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-23
Engine Coolant.............................................5-26
Radiator Pressure Cap..................................5-28
Engine Overheating.......................................5-28
Cooling System............................................5-30Engine Fan Noise.........................................5-35
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-42
Rear Axle.......................................................5-46
Four-Wheel Drive............................................5-47
Front Axle......................................................5-48
Headlamp Aiming...........................................5-49
Bulb Replacement..........................................5-49
Halogen Bulbs..............................................5-49
Headlamps..................................................5-50
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-51
Taillamps, Turn Signal, and Stoplamps............5-51
Back-Up Lamps............................................5-53
License Plate Lamp......................................5-53
Replacement Bulbs.......................................5-54
Windshield Wiper Blade Replacement..............5-54
Tires..............................................................5-57
Tire Sidewall Labeling...................................5-58
Tire Terminology and Denitions.....................5-61
Ination - Tire Pressure.................................5-64
Section 5 Service and Appearance Care
5-1