2008 GMC ENVOY Maintenance

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

Restraint System Check
Checking the Restraint Systems
Safety Belts
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.
Make sure the safety belt reminder light is working.
SeeSafety Belt Reminders on page 3-32for more
information.
Keep safety belts clean and dry. SeeCare of Safety
Belts on page 5-103.
Airbags
The airbag system does not need regularly scheduled
maintenance or replacement. Make sure the airbag
readiness light is working. SeeAirbag Readiness
Light on page 3-33for more information.
Notice:If an airbag covering is damaged, opened,
or broken, the airbag may not work properly.
Do not open or break the airbag coverings. If there
are any opened or broken airbag covers, have
the airbag covering and/or airbag module replaced.
For the location of the airbag modules, seeWhat
Makes an Airbag Inflate? on page 1-59.
See your dealer/retailer for service.
1-68

Malfunctions often are indicated by the system before
any problem is apparent. This can 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 a while, the emission controls
might not work as well, your vehicle’s fuel economy
might not be as good, and the engine might not
run as smoothly. This could lead to costly repairs
that might 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 can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.This light comes on, as a check to show it is working,
when the ignition is turned ON/RUN but the engine is not
running. If the light does not come on, have it repaired.
This light also comes on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system
on your vehicle. Diagnosis and service might
be required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
3-42

Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
might 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 the battery or if the battery
has run down. The diagnostic system is designed to
evaluate critical emission control systems during normal
driving. This can 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
dealer/retailer 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).United States
Canada
3-44

{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.
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 other problems causing
low oil pressure.
Change Engine Oil Light
Your vehicle may have a
change engine oil light.
When this light comes on it means that an oil change
and other maintenance procedures are required for your
vehicle.
SeeScheduled Maintenance on page 6-4andEngine
Oil on page 5-16for more information.
Once the engine oil has been changed, the change
engine oil light must be reset. Until it is reset, the light
will stay on when the engine is on.
3-45

Fuel Information Button
t
(Fuel Information):Press the fuel information
button to scroll through the range, fuel used, average
fuel economy, and the engine oil life system.
Fuel Range:Press the fuel information button until
RANGE appears on the display. This mode shows the
remaining distance you can drive without refueling.
It is based on fuel economy and the fuel remaining
in the fuel tank. The display will show LOW if the fuel
level is low.
The fuel economy data used to determine fuel range is
an average of recent driving conditions. As your driving
conditions change, this data is gradually updated. Fuel
range cannot be reset.
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), liters per
100 kilometers (L/100 km), or kilometers per liter (km/L)
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 the 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, seeEngine
Oil Life System on page 5-19.
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 5-16andScheduled Maintenance on
page 6-4.
3-52

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 3-58for more information.
Select Button
r
(Select):Press the select button to reset certain
DIC functions, turn off or acknowledge messages on
the DIC display, and set your customization settings.
For example, this button will allow you to reset the trip
odometers, turn off the FUEL LEVEL LOW message,
and enables you to scroll through and select the
language in which the DIC information will appear.
DIC Warnings and Messages
Messages are displayed on the DIC to notify the driver
that the status of the vehicle has changed and that
some action may be needed to correct the condition.
Multiple messages may appear one after another.Some messages may not require immediate action.
Press any of the DIC buttons on the steering wheel or
the trip odometer reset stem on the instrument panel
cluster to acknowledge that you received the messages
and to 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.
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.
CHANGE ENGINE OIL
This message displays when the engine oil needs to
be changed and service is required for your vehicle.
SeeScheduled Maintenance on page 6-4andEngine
Oil on page 5-16for more information. Also seeEngine
Oil Life System on page 5-19for information on how
to reset the message. This message clears itself
after 10 seconds until the next ignition cycle.
3-53

“Off-roading” means you have left the great North
American road system behind. Traffic lanes are
not marked. Curves are not banked. There are no
road signs. Surfaces can be slippery, rough, uphill, or
downhill. In short, you have gone right back to nature.
Off-road driving involves some new skills. And that
is why it is very important that you read this guide.
You will nd many driving tips and suggestions. These
will help make your off-road driving safer and more
enjoyable.
Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields, if the vehicle has them, are
properly attached.
Be sure you read all the information about your
four-wheel-drive vehicle in this manual.
Is there enough fuel? Is the spare tire fully inated?
Are the uid levels up where they should be? What
are the local laws that apply to off-roading where you will
be driving? If you do not know, you should check with
law enforcement people in the area. Will you be on
someone’s private land? If so, be sure to get the
necessary permission.
Loading Your Vehicle for Off-Road
Driving
{CAUTION:
Cargo on the load oor piled higher than
the seatbacks can be thrown forward during
a sudden stop. You or your passengers
could be injured. Keep cargo below the
top of the seatbacks.
Unsecured cargo on the load oor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by ying objects. Secure the cargo
properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as far forward
and low as possible.
4-14