2008 GMC ENVOY ECO mode

In any particular crash, no one can say whether an
airbag should have inated simply because of the
damage to a vehicle or because of what the repair
costs were. For frontal airbags, ination is determined
by what the vehicle hits, the angle of the impact,
and how quickly the vehicle slows down. For roof-rail
airbags, deployment is determined by the location
and severity of the side impact. In a rollover event,
roof-rail airbag deployment is determined by the
direction of the roll.
What Makes an Airbag Inate?
In a deployment event, the sensing system sends
an electrical signal triggering a release of gas from
the inator. Gas from the inator lls the airbag causing
the bag to break out of the cover and deploy. The
inator, the airbag, and related hardware are all part
of the airbag module.
Frontal airbag modules are located inside the steering
wheel and instrument panel. For vehicles with roof-rail
airbags, there are airbag modules in the ceiling of the
vehicle, near the side windows that have occupant
seating positions.
How Does an Airbag Restrain?
In moderate to severe frontal or near frontal collisions,
even belted occupants can contact the steering wheel
or the instrument panel. In moderate to severe side
collisions, even belted occupants can contact the inside
of the vehicle.
Airbags supplement the protection provided by safety
belts. Frontal airbags distribute the force of the impact
more evenly over the occupant’s upper body, stopping
the occupant more gradually. Roof-rail airbags distribute
the force of the impact more evenly over the occupant’s
upper body.
Rollover capable roof-rail airbags are designed to
help contain the head and chest of occupants in the
outboard seating positions in the rst and second rows.
The rollover capable roof-rail airbags are designed to
help reduce the risk of full or partial ejection in rollover
events, although no system can prevent all such
ejections.
But airbags would not help in many types of collisions,
primarily because the occupant’s motion is not toward
those airbags. SeeWhen Should an Airbag Inflate? on
page 1-58for more information.
Airbags should never be regarded as anything more
than a supplement to safety belts.
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Programming Delayed Locking
To turn the delayed locking feature on or off, do the
following:
1. Press and hold the power door lock switch on the
driver’s door in the lock position.
2. Press the remote keyless entry transmitter unlock
button twice.
If the delayed locking feature was on, it will now be off.
If the feature was off, it will now be on.
Programmable Automatic Door
Locks
Your vehicle is equipped with an automatic lock/unlock
feature which enables you to program your vehicle’s
power door locks. You can program this feature through
the Driver Information Center (DIC), or by the following
method. SeeDIC Vehicle Customization on page 3-58.
Programmable Locking Feature
Following are the two locking modes that can be
programmed:
Mode 1:All doors lock when the transmission is shifted
out of PARK (P).
Mode 2:All doors lock when the vehicle speed is
greater than 8 mph (13 km/h).The automatic door locks were pre-programmed at the
factory to lock all the doors when the transmission
is shifted into gear. The following instructions detail how
to program your door locks differently than the factory
setting. Choose one of the two programming options
listed previously before entering the program mode.
To enter the program mode, do the following:
1. Begin with the ignition off. Then pull the turn
signal/multifunction lever toward you and hold
it there while you perform the next step.
2. Turn the key to RUN and LOCK twice. Then, with
the key in LOCK, release the turn signal/multifunction
lever. Once you do this, you will hear the lock switch
lock and unlock, the horn will chirp twice, and a
30-second program timer will begin.
3. You are now ready to program the automatic door
locks. Select one of the two programming options
listed previously, and press the lock side of the
power door lock switch to cycle through the lock
options. You will have 30 seconds to begin
programming. If you exceed the 30-second limit,
the locks will automatically lock and unlock and the
horn will chirp twice to indicate that you have left
the program mode. If this occurs, repeat the
procedure beginning with Step 1 to re-enter
the programming mode.
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You can exit the program mode any time by turning the
ignition to RUN. The locks will automatically lock and
unlock and the horn will chirp twice to indicate that you
are leaving the program mode. If the lock/unlock switches
are not pressed while in the programming mode, the
current auto lock/unlock setting will not be modied.
See your dealer for more information.
Programmable Unlocking Feature
The following is the list of available programming
options:
Mode 1:Driver’s door unlocks when the transmission is
shifted into PARK (P).
Mode 2:All doors unlock when the transmission is
shifted into PARK (P).
Mode 3:All doors unlock when the key is removed
from the ignition.
Mode 4:No automatic door unlock.
The automatic door locks were pre-programmed at the
factory to unlock all doors once the transmission is shifted
to PARK (P). The following instructions detail how to
program your door locks differently than the factory
setting. Choose one of the four programming options
listed previously before entering the program mode.To enter the program mode you need to do the
following:
1. Begin with the ignition off. Then pull the turn
signal/multifunction lever toward you and hold
it there while you perform the next step.
2. Turn the key to RUN and LOCK twice. Then, with the
key in LOCK, release the turn signal/multifunction
lever. Once you do this, you will hear the lock switch
lock and unlock, the horn will chirp twice, and a
30-second program timer will begin.
3. You are now ready to program the automatic door
locks. Select one of the four programming options
listed above, and press the unlock side of the power
door lock switch to cycle through the unlocking
options. You will have 30 seconds to begin
programming. If you exceed the 30-second limit,
the locks will automatically lock and unlock and
the horn will chirp twice to indicate that you have
left the program mode. If this occurs, repeat the
procedure beginning with Step 1 to re-enter the
programming mode.
You can exit the program mode any time by turning the
ignition to RUN. The locks will automatically lock and
unlock and the horn will chirp twice to indicate that
you are leaving the program mode. If the lock/unlock
switches are not pressed while in the programming
mode, the current auto lock/unlock setting will not
be modied.
See your dealer for more information.
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{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.
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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.
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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

Automatic Dimming Mirror Operation
The automatic dimming mirror comes on each time the
ignition is turned to start. To turn the automatic dimming
feature off or back on, press the on/off button. The
indicator light on the mirror is lit when the automatic
dimming feature is on.
Compass Operation
Press the on/off button once to turn the compass
on or off.
There is a compass display in the window in the upper
right corner of the mirror face.
Compass Calibration
Press and hold the on/off button to activate the compass
calibration mode. CAL will be displayed in the compass
window on the mirror.
The compass can be calibrated by driving the vehicle
in circles at 5 mph (8 km/h) or less until the display
reads a direction.If after a few seconds the display does not show a
compass direction, (N for North for example), there may
be a strong magnetic eld interfering with the compass.
Such interference may be caused by a magnetic antenna
mount, note pad holder, or similar object. If the letter C or
CAL appears in the compass window, the compass may
need to be reset or calibrated.
Compass Variance
Compass variance is the difference between earth’s
magnetic north and true geographic north. The mirror
is set to zone eight upon leaving the factory. It will be
necessary to adjust the compass to compensate for
compass variance if you live outside zone eight. Under
certain circumstances, such as during a long distance
cross-country trip, it will be necessary to adjust for
compass variance. If not adjusted to account for compass
variance, your compass could give false readings.
2-40

Automatic Dimming Mirror Operation
The automatic dimming mirror function is turned
on automatically each time the ignition is started. To
operate the automatic dimming mirror, do the following:
1. Make sure the green indicator light, located to
the left of the on/off button, is lit. If it’s not, press
and hold the on/off button until the green light
comes on, indicating that the mirror is in automatic
dimming mode.
2. Turn off the automatic dimming mirror function by
pressing and holding the on/off button until the
green indicator light turns off.
Temperature and Compass Display
Press the on/off button, located to the far left, briey to
turn the compass/temperature display on or off.
If the display reads CAL, you will need to calibrate
the compass. For more information on calibration,
see below.To adjust between Fahrenheit and Celsius, do the
following:
1. Press and hold the on/off button until either a
ashing F or C appears.
2. Press the button again to change the display to the
desired unit of measurement. After approximately
four seconds of inactivity, the new unit will be locked
in and the display will return.
If an abnormal temperature reading is displayed for an
extended period of time, please consult your dealer.
Under certain circumstances, a delay in updating
the temperature is normal.
Compass Variance
The mirror is set in zone eight upon leaving the factory.
It will be necessary to adjust the compass to compensate
for compass variance if you live outside of zone eight.
Under certain circumstances, as during a long distance
cross-country trip, it will be necessary to adjust for
compass variance. Compass variance is the difference
between earth’s magnetic north and true geographic
north. If not adjusted to account for compass variance,
your compass could give false readings.
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