2008 GMC ENVOY fuel

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

Keys...............................................................2-3
Remote Keyless Entry (RKE) System................2-4
Remote Keyless Entry (RKE) System
Operation...................................................2-5
Doors and Locks.............................................2-7
Door Locks....................................................2-7
Power Door Locks..........................................2-8
Delayed Locking.............................................2-8
Programmable Automatic Door Locks................2-9
Rear Door Security Locks..............................2-11
Lockout Protection........................................2-11
Liftgate/Liftglass............................................2-12
Windows........................................................2-13
Power Windows............................................2-14
Sun Visors...................................................2-15
Theft-Deterrent Systems..................................2-16
Content Theft-Deterrent.................................2-16
Passlock
®(U. S. Only)..................................2-17
PASS-Key®III+............................................2-18
PASS-Key®III+ Operation (Canada Only).........2-18
Starting and Operating Your Vehicle................2-20
New Vehicle Break-In....................................2-20
Ignition Positions..........................................2-21Retained Accessory Power (RAP)...................2-22
Starting the Engine.......................................2-22
Adjustable Throttle and Brake Pedal................2-24
Engine Coolant Heater..................................2-24
Active Fuel Management™.............................2-25
Automatic Transmission Operation...................2-26
Four-Wheel Drive..........................................2-29
Parking Brake..............................................2-33
Shifting Into PARK (P)...................................2-34
Shifting Out of PARK (P)...............................2-36
Parking Over Things That Burn.......................2-37
Engine Exhaust............................................2-37
Running the Vehicle While Parked..................2-38
Mirrors...........................................................2-39
Manual Rearview Mirror.................................2-39
Manual Rearview Mirror with OnStar
®..............2-39
Automatic Dimming Rearview Mirror with
OnStar
®and Compass...............................2-39
Automatic Dimming Rearview Mirror with
OnStar
®, Compass and Temperature
Display....................................................2-41
Automatic Dimming Rearview Mirror with
Compass and Temperature Display..............2-44
Section 2 Features and Controls
2-1

Testing the Alarm
To test the alarm:
1. From inside the vehicle, lower the driver’s window
and open the driver’s door.
2. Activate the system by locking the doors with the
power door lock switch while the door is open, or
with the RKE transmitter.
3. Get out of the vehicle, close the door and wait for
the security light to go out.
4. Then reach in through the window, unlock the door
with the manual door lock and open the door.
This should set off the alarm.
When the alarm is set the power door unlock switch will
not work.
If the alarm does not sound when it should but the
headlamps ash, check to see if the horn works.
The horn fuse may be blown. To replace the fuse,
seeFuses and Circuit Breakers on page 5-110.
If the alarm does not sound or the headlamps do
not ash, the vehicle should be serviced by your
dealer/retailer.
Passlock®(U. S. Only)
Your vehicle has the Passlock®theft-deterrent system.
Passlock®is a passive theft-deterrent system that
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 has been tampered with, the fuel system is
disabled and the vehicle will not start.
During normal operation, the security light will turn off
about ve seconds after the key is turned to ON/RUN.
If the engine stalls and the security light ashes,
wait about 10 minutes 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 does not start after three tries, the vehicle
needs service.
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/retailer.
Your vehicle is not protected by Passlock
®at this time.
You may also want to check the fuse. SeeFuses and
Circuit Breakers on page 5-110. See your dealer/retailer
for service.
In an emergency, call the Roadside Assistance Center.
SeeRoadside Assistance Program on page 7-8.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.
2-17

Adjustable Throttle and Brake Pedal
If your vehicle has this feature, you can change the
position of the throttle and brake pedals. This feature is
designed for shorter drivers, since the pedals cannot
move farther away from the standard position, but can
move closer for better pedal reach.
The vehicle must be in PARK (P) for this feature to
operate.
The switch used to adjust
the pedals is located on
the steering column.
Press the switch forward or backward to move the
pedals closer or farther away from you.
Engine Coolant Heater
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above 0°F (−18°C).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located on the driver’s side of the
engine compartment next to the battery box
facing the engine.
3. Plug it into a normal, grounded 110-Volt AC outlet.
2-24

{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could
be damaged.
How long should you keep the coolant heater plugged in?
The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead of
trying to list everything here, we ask that you contact your
dealer in the area where you will be parking your vehicle.
The dealer/retailer can give you the best advice for that
particular area.
Active Fuel Management™
Your vehicle’s V8 engine may have Active Fuel
Management™. This system allows the engine to
operate on either all or half of its cylinders, depending
on your driving conditions.
When less power is required, such as cruising at a
constant vehicle speed, the system will operate in the
half cylinder mode, allowing your vehicle to achieve
better fuel economy. When greater power demands are
required, such as accelerating from a stop, passing,
or merging onto a freeway, the system will maintain
full-cylinder operation.
2-25

DRIVE (D):This position is for normal driving.
It provides the best fuel economy for your vehicle.
If you need more power for passing, and you are:
Going less than about 35 mph (55 km/h), push the
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
You will shift down to the next gear and have more
power.
Downshifting the transmission in slippery road conditions
could result in skidding, see “Skidding” underLoss of
Control on page 4-12.
DRIVE (D) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road driving.
You may want to shift the transmission to THIRD (3) or,
if necessary, a lower gear selection if the transmission
shifts too often.
THIRD (3):This position is also used for normal driving.
It reduces vehicle speed more than DRIVE (D) without
using your brakes. You might choose THIRD (3) instead
of DRIVE (D) when driving on hilly, winding roads,
when towing a trailer, so there is less shifting between
gears and when going down a steep hill.
To shift to the THIRD (3) position, you must rst press
the large button on the shift handle. While the button
is pressed, move the shifter in the THIRD (3) position.SECOND (2):This position reduces vehicle speed even
more than THIRD (3) without using your brakes. You can
use SECOND (2) on hills. It can help control your speed
as you go down steep mountain roads, but then you
would also want to use your brakes off and on.
To shift to the SECOND (2) position, you must rst press
the large button on the shift handle. While the button is
pressed, move the shifter in the SECOND (2) position.
You can also use SECOND (2) for starting the vehicle
from a stop on slippery road surfaces.
FIRST (1):This position reduces vehicle speed even
more than SECOND (2) without using your brakes.
You can use it on very steep hills, or in deep snow
or mud. If the shift lever is put in FIRST (1) while the
vehicle is moving forward, the transmission will not shift
into rst gear until the vehicle is going slowly enough.
To shift to the FIRST (1) position, you must rst press
the large button on the shift handle. While the button is
pressed, move the shifter in the FIRST (1) position.
Notice:Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator pedal
may damage the transmission. The repair will not be
covered by your warranty. If you are stuck, do not
spin the tires. When stopping on a hill, use the brakes
to hold the vehicle in place.
2-28

Four-Wheel Drive
If your vehicle has four-wheel drive, the engine’s driving
power can be sent to all four wheels for extra traction.
To get the most satisfaction out of four-wheel drive, you
must be familiar with its operation. Read the part that
follows before using four-wheel drive. You should
use Two-Wheel High for most normal driving conditions.
Notice:Driving on clean, dry pavement in
Four-Wheel-Drive High or Four-Wheel-Drive Low for
an extended period of time may cause premature
wear on your vehicle’s powertrain. Do not drive on
clean, dry pavement in Four-Wheel-Drive High or
Four-Wheel-Drive Low for extended periods of time.
Notice:If you continually drive your vehicle with
the transfer case in AUTO or Four-Wheel Drive, you
could shorten the life of the transfer case or the
Four-Wheel Drive system. The selector switch
should be left in Two-Wheel Drive High mode. Only
use AUTO and Four-Wheel Drive when you need
extra traction such as in wet or slippery road
conditions.
Automatic Transfer Case
If your vehicle has four-wheel drive, the transfer case
knob is located to the right of the steering wheel on the
instrument panel.
Use this knob to shift into
and out of four-wheel drive
2
m(Two-Wheel High):This setting is for driving in
most street and highway situations. Your front axle is not
engaged in two-wheel drive. It also provides the best
fuel economy.
2-29

AUTO (Automatic Four-Wheel Drive):This setting is
ideal for use when road conditions are variable. When
driving your vehicle in automatic four-wheel drive, the
front axle is engaged, but the vehicle’s power is sent to
the rear wheels. When the vehicle senses a loss of
traction, the system will automatically engage four-wheel
drive. Driving in this mode results in slightly lower fuel
economy than Two-Wheel High.
4
m(Four-Wheel High):This setting should be used
when you need extra traction, such as on snowy or
icy roads or in most off-road situations. This setting also
engages your front axle to help drive your vehicle.
4
n(Four-Wheel Low):This setting also engages
your front axle and delivers extra torque. It sends
maximum power to all four wheels. You might choose
this setting if you are driving off-road in deep sand,
deep mud, and climbing or descending steep hills.
{CAUTION:
Shifting the transfer case to NEUTRAL
can cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. SeeParking Brake on
page 2-33.
NEUTRAL:Shift the vehicle’s transfer case
to NEUTRAL only when towing your vehicle.
SeeRecreational Vehicle Towing on page 4-40
for more information.
An indicator light in the knob will show you which
position the transfer case is in. The indicator lights will
come on briey when you turn on the ignition and one will
stay on. If the lights do not come on, you should take your
vehicle to your dealer for service. An indicator light will
ash while shifting the transfer case. It will stay on when
the shift is complete. If for some reason the transfer case
cannot make a requested shift, it will return to the last
chosen setting.
If the service Four-Wheel Drive Warning Light on the
instrument panel cluster stays on, you should take
your vehicle to your dealer for service. SeeService
Four-Wheel Drive Warning Light on page 3-47for
further information.
2-30