light GMC ENVOY 2008 Service Manual

Headlamps on Reminder
A reminder tone sounds when the headlamps or parking
lamps are manually turned on, if the driver’s door is
open and the ignition is in LOCK or ACC. To turn the
tone off, turn the knob all the way counterclockwise.
In the automatic mode, the headlamps turn off once the
ignition key is in LOCK.
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier
for others to see the front of your vehicle during the day.
DRL can be helpful in many different driving conditions,
but they can be especially helpful in the short periods
after dawn and before sunset. Fully functional DRL
are required on all vehicles rst sold in Canada.
The DRL system makes the headlamps come on at
reduced brightness when the following conditions
are met:
The ignition is on.
The exterior lamps knob is in automatic
headlamp mode.
The light sensor detects daytime light.
The transmission is not in PARK (P).When the DRL are on, only the headlamps will be on.
The taillamps, sidemarker and other lamps will not
be on. The instrument panel will not be lit up either.
When it begins to get dark, the headlamps automatically
switch from DRL to the regular headlamps.
Automatic Headlamp System
When it is dark enough outside, the Automatic
Headlamp System turns on the headlamps when the
vehicle is started and after the transaxle has been
shifted out of the PARK (P) position. The headlamps,
taillamps, sidemarker, and parking lamps will come
on. The instrument panel lights and radio lights will
also turn on at normal brightness. Once on, the system
remains on during these conditions even if the vehicle
is shifted back into PARK (P).
The vehicle has a light sensor on the top of the
instrument panel. Make sure it is not covered or the
system may come on whenever the ignition is on and
the vehicle is shifted out of the PARK (P) position.
The system could also turn on the lamps when driving
through a parking garage, heavy overcast weather
or a tunnel. This is normal.
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There is a delay in the transition between the daytime and
nighttime operation of the Daytime Running Lamps (DRL)
and the automatic headlamp systems, so that driving
under bridges or bright overhead street lights does not
affect the system. The DRL and automatic headlamp
system are only affected when the light sensor sees a
change in lighting lasting longer than the delay.
If you start your vehicle in a dark garage, the automatic
headlamp system comes on after the transmission is
shifted out of PARK (P). Once you leave the garage,
it will take about one minute for the automatic headlamp
system to change to DRL if it is light outside. During
that delay, the instrument panel cluster might not be
as bright as usual. Make sure the instrument panel
brightness control is in the full bright position.
If the vehicle is running and the automatic headlamp
system is already on, it can be turned off by turning
and releasing the headlamp control at the off position.
The automatic headlamp system stays off until you
turn and release the headlamp control at the off
position again. SeeHeadlamps on page 3-14.Fog Lamps
Use the fog lamps for better vision in foggy or misty
conditions. The ignition must be in RUN for the
fog lamps to work.
The fog lamp button is
located on the instrument
panel to the right of the
exterior lamps knob.
Press the button to turn the fog lamps on. Press the
button again to turn them off. A light glows near the
button while the fog lamps are on. Fog lamps turn off
whenever the high-beam headlamps are on.
Some localities have laws that require the headlamps to
be on along with the fog lamps.
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Instrument Panel Brightness
Press the knob located
next to the exterior lamps
knob to extend it.
Turn the knob to adjust the instrument panel lights. Turn
the knob all the way up to turn on the interior lamps.
Press the knob back into its stored position when
you are not using it.
Dome Lamps
The dome lamps will come on when you open a door
unless the dome lamp override is pressed in.
Dome Lamp Override
The dome override button
is located below the
exterior lamps knob.
To turn the dome lamps off, press the button. The dome
lamps will remain off when a door is open. This will
override the illuminated entry feature unless you use the
Remote Keyless Entry (RKE) transmitter to unlock the
vehicle.
To return the lamps to automatic operation, press the
button again. The dome lamps come on when a door is
opened.
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Entry Lighting
The vehicle has entry lighting.
When any door is opened, the dome lamps come on as
long as the dome override lamp override button is not
pressed in. When all the doors are closed, the lamps
stay on for a short period of time and then turn off
automatically. If you use the Remote Keyless Entry (RKE)
transmitter to unlock the vehicle, the interior lamps come
on for a short time whether or not the dome lamp override
is on.
Exit Lighting
With exit lighting, the interior lamps come on when you
remove the key from the ignition. If the dome override
is off, these lamps stay on for a short period of time
and then go out.
Reading Lamps
The reading lamps are located in the front console.
Press the lens on the lamps to turn the reading lamps
on or off.
Electric Power Management
The vehicle has Electric Power Management (EPM)
that estimates the battery’s temperature and state
of charge. It then adjusts the voltage for best
performance and extended life of the battery.
When the battery’s state of charge is low, the voltage is
raised slightly to quickly put the charge back in. When
the state of charge is high, the voltage is lowered slightly
to prevent overcharging. If the vehicle has a voltmeter
gage or a voltage display on the Driver Information
Center (DIC), you may see the voltage move up
or down. This is normal. If there is a problem, an
alert will be displayed.
The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles. This is
because the generator (alternator) may not be spinning
fast enough at idle to produce all the power that is
needed for very high electrical loads.
A high electrical load occurs when several of the
following loads are on: headlamps, high beams, fog
lamps, rear window defogger, climate control fan at
high speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.
3-18

Accessory Power Outlet(s)
With the accessory power outlets, you can plug in
auxiliary electrical equipment such as a cellular
telephone or CB radio.
Your vehicle has three accessory power outlets.
There are two outlets located below the climate
controls and one outlet is on the rear of the center
oor console.
Remove the cover from the outlet to use the outlet.
Be sure to put the cover back on when not using the
accessory power outlet.
Certain electrical accessories may not be compatible
with the accessory power outlet and could result
in blown vehicle or adaptor fuses. If you experience
a problem, see your dealer for additional information
on the accessory power outlets.
Notice:Adding any electrical equipment to your
vehicle may damage it or keep other components
from working as they should. The repairs would not
be covered by your warranty. Do not use equipment
exceeding maximum amperage rating of 20 amperes.
Check with your dealer/retailer before adding
electrical equipment.
When adding electrical equipment, be sure to follow
the proper installation instructions included with the
equipment.Notice:Improper use of the power outlet can cause
damage not covered by your warranty. Do not
hang any type of accessory or accessory bracket
from the plug because the power outlets are
designed for accessory power plugs only.
Ashtray(s) and Cigarette Lighter
Your vehicle may have this feature. The ashtray is
removable and ts into the front cupholder.
Notice:If you put papers, pins, or other ammable
items in the ashtray, hot cigarettes or other smoking
materials could ignite them and possibly damage
your vehicle. Never put ammable items in the
ashtray.
To remove the ashtray, pull the covered bin out of the
cupholder.
To use the lighter, press it in all the way, and let go.
When it is ready, it will pop back out by itself.
Notice:Holding a cigarette lighter in while it is
heating will not allow the lighter to back away from
the heating element when it is hot. Damage from
overheating may occur to the lighter or heating
element, or a fuse could be blown. Do not hold a
cigarette lighter in while it is heating. Do not use
equipment exceeding maximum amperage rating
of 20 amperes.
3-20

Climate Controls
Dual Climate Control System
With this system you can control the heating, cooling,
and ventilation for your vehicle.
9(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the
fan speed. If the knob is in off mode, outside air still
enters the vehicle, and is directed based on the position
of the mode knob. The temperature can still be adjusted
using the temperature knob.
Turn the right knob clockwise or counterclockwise to
direct the airow inside of your vehicle.To change the current mode, select one of the following:
H(Vent):This mode directs air to the instrument
panel outlets.
)(Bi-Level):This mode directs about half of the air
to the instrument panel outlets; then directs most of
the remaining air to the oor outlets. A little air is
directed toward the windshield and the side window
outlets. Cooler air is directed to the upper vents
and warmer air to the oor outlets.
6(Floor):This mode directs most of the air to the
oor outlets with a little air directed to the windshield
and the side window outlets. The recirculation button
cannot be selected while in oor mode.
@(Recirculation):Recirculation mode is used to
recirculate the air inside of your vehicle. When this button
is pressed, an indicator light in the button will come on
to let you know that it is active. Use this mode to help
prevent outside odors and/or dust from entering your
vehicle or to help cool the air inside of your vehicle more
quickly. The air conditioning compressor will also come
on when this mode is activated. While in recirculation
mode, the windows may fog when the weather is cold
and damp. To clear the fog, select either the defog or
defrost mode and increase fan speed.
Defog and defrost modes are described later in this
section.
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Driver’s Side Temperature Lever:The lever on the
left side of the climate control panel is used to raise
or lower the temperature on the driver’s side of
the vehicle. Slide the lever up or down to adjust
the temperature.
Passenger’s Side Temperature Lever:The lever on
the right side of the climate control panel is used to raise
or lower the temperature on the passenger’s side of
the vehicle. Slide the lever up or down to adjust the
temperature. This lever also adjusts the temperature
to the rear seat outlets.
When the temperature outside is 0°F (−18°C) or lower,
use the engine coolant heater, if the vehicle has
one, to provide warmer air, faster to your vehicle.
#(Air Conditioning):Press this button to turn the
air-conditioning system on or off. When the button is
pressed, an indicator light will come on and the system
will begin to cool and dehumidify the air inside of the
vehicle. You may notice a slight change in engine
performance when the air conditioning compressor
shuts off and turns on again. This is normal.
Defogging and Defrosting
Fog on the inside of windows is a result of high humidity
(moisture) condensing on the cool window glass. This
can be minimized if the climate control system is used
properly. There are two modes to choose from to clear
fog or frost from your windshield. Use the defog mode
to clear the windows of fog or moisture and warm the
passengers. Use the defrost mode to remove fog or
frost from the windshield more quickly.
Turn the right knob clockwise or counterclockwise to
select one of the following modes:
-(Defog):This mode directs the air to the
oor outlets, windshield and side window outlets.
The recirculation button cannot be selected while in
defog mode.
1(Defrost):This mode directs most of the air to the
windshield and the side window outlets, with only a little
air directed to the oor outlets. The air conditioning
compressor may run to dehumidify the air to prevent
window fogging. The recirculation button cannot be
selected while in defrost mode. Do not drive the vehicle
until all the windows are clear.
3-22

Rear Window Defogger
If your vehicle has the rear window defogger a warming
grid is used to remove fog on the rear window.
<(Rear):Press this button to turn the rear window
defogger on or off. An indicator light in the button
will come on to let you know that the rear window
defogger is active. The rear window defogger will
automatically turn off approximately ten minutes
after the button is pressed.
If your vehicle has heated mirrors, this button will
activate them.
Notice:Do not use anything sharp on the inside of
the rear window. If you do, you could cut or damage
the warming grid, and the repairs would not be
covered by your warranty. Do not attach a temporary
vehicle license, tape, a decal or anything similar to
the defogger grid.
Dual Automatic Climate Control
System
With this system you can control the heating, cooling
and ventilation for your vehicle. When your vehicle
is rst started and the climate control system is on,
or if the climate control system has been turned on,
the display will show the driver’s temperature setting for
ve seconds. Then it will show the outside temperature.
3-23

6(Floor):This mode directs most of the air to the
oor outlets. Some air also comes out of the defroster
and side window outlets. The recirculation button
cannot be selected in oor mode.
@(Recirculation):Press this button to turn
recirculation mode on or off. When this button is pressed,
an indicator light in the button will also come on to let you
know that it is activated. Recirculation mode is used to
recirculate the air inside of your vehicle. Use this mode to
help prevent outside odors and/or dust from entering your
vehicle or to help cool the air inside of your vehicle more
quickly. Recirculation mode can be used with vent and
bi-level modes, but it cannot be used with oor, defog or
defrost modes. Defog and defrost modes are described
later in this section.
If recirculation mode is selected with oor, defog, or
defrost modes, the indicator will ash three times and
then turn off indicating the selection is not available.
You may also notice that the air conditioning compressor
will run while in recirculation mode. This is normal and will
help to prevent fogging.
If the weather is cold and damp, the system may cause
the windows to fog while using recirculation mode. If the
windows do start to fog, select defog or defrost mode and
increase fan speed.
Recirculation mode, if selected, will be cleared when the
engine is turned off.
#A/C (Air Conditioning):Press this button to
manually turn the air conditioning system on or off.
When the system is on, the system will automatically
begin to cool and dehumidify the air inside of your
vehicle. The air conditioning symbol will appear on the
display when the air conditioning is on and will turn
off when the air conditioning is off.
If you turn the air conditioning off while in front defrost
or defog mode, the air conditioning symbol will turn
off, however, the A/C compressor will remain on to help
de-humidify the air inside the vehicle. If one of the
other modes is selected the compressor will then turn
the A/C off until it is selected again or the AUTO button
is pressed.
To avoid fogging the inside glass on rainy and humid
days at a temperature above freezing, press the air
conditioning button to run the A/C compressor. Also it is
best to avoid the use of the recirculation mode except
when maximum air conditioning performance is needed
or for short times to avoid exterior odors.
You may notice a slight change in engine performance
when the air-conditioning compressor shuts off and turns
on again. This is normal.
3-26

Defogging and Defrosting
Fog on the inside of the windows is a result of moisture
condensing on the cool window glass. This can be
reduced if the climate control system is used properly.
You can use either defog or front defrost to clear
fog or frost from your windshield.
-(Defog):Use this setting to clear the windows of
fog or moisture. This setting will deliver air to the
oor and windshield outlets.
0(Front Defrost):Press the front defrost button to
clear the windshield and side windows of frost or fog
quickly. The system will automatically control the fan
speed if you select defrost from AUTO mode. If the
outside temperature is 40°F (4°C) or warmer, your air
conditioning compressor will automatically run to help
dehumidify the air and dry the windshield. Do not drive
the vehicle until all the windows are clear.
Rear Window Defogger
If your vehicle has the rear window defogger a warming
grid is used to remove fog from the rear window.
<(Rear):Press this button to turn the rear window
defogger on or off.
An indicator light in the button will come on to let you
know that the rear window defogger is activated.
The rear window defogger will turn off approximately
10 minutes after the button is pressed. If you need
additional warming time, press the button again.
If your vehicle has heated mirrors, they will come on
when this button is pressed.
Notice:Do not use a razor blade or sharp object to
clear the inside rear window. Do not adhere anything
to the defogger grid lines in the rear glass. These
actions may damage the rear defogger. Repairs
would not be covered by your warranty.
3-27