light GMC YUKON XL 2007 Repair Manual

9(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the fan
speed. Turn the knob all the way counterclockwise
to turn the front system off.
?(Recirculation):Press this button to turn
the recirculation mode on. When the button
is pressed, an indicator light will come on.
This mode keeps outside air from entering the
vehicle. It can be used to reduce outside air and
prevent odors from entering your vehicle.
Recirculation may also help cool the air inside
your vehicle more quickly once the temperature
inside the vehicle is less than the outside
temperature.
The recirculation mode cannot be used with oor,
defrost, or defogging modes. If you try to select
recirculation in one of those modes, the indicator
will ash three times and turn off. 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 the fan speed.
Recirculation mode can be turned off by pressing
the button again, or turning off the engine.AUX (Auxiliary):Pressing this button will turn the
rear heating and air conditioning on. SeeRear
Air Conditioning and Heating System on page 220
orRear Air Conditioning and Heating System
and Electronic Climate Controls on page 222for
more information.
Temperature Control:Rotate the thumbwheels
up or down to increase or decrease the
temperature on the driver’s side or the passenger
side of the vehicle for the dual zone system.
#(Air Conditioning):Press this button on the
left knob to turn the air conditioning system on
or off. When A/C is pressed, an indicator light will
come on to let you know that the air conditioning
has been activated.
On hot days, open the windows to let hot inside
air escape; then close them. This helps to reduce
the time it takes for your vehicle to cool down.
It also helps the system to operate more efficiently.
The air conditioning system removes moisture
from the air, so you may sometimes notice a small
amount of water dripping underneath your
vehicle while idling or after turning off the engine.
This is normal.
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Automatic Operation
AUTO (Automatic):When automatic operation
is active the system will control the inside
temperature, the air delivery, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the display will
change to show the current temperature(s)
and AUTO will be lit on the display. The current
delivery mode and fan speed will also be
displayed for approximately 5 seconds.
When AUTO is selected, the air conditioning
operation and air inlet will be automatically
controlled. The air conditioning compressor will
run when the outside temperature is over
about 40°F (4°C). The air inlet will normally be
set to outside air. If it’s hot outside, the air
inlet may automatically switch to recirculate
inside air to help quickly cool down your
vehicle. The light on the button will illuminate
in recirculation.2. Set the driver’s and passenger’s temperature.
To nd your comfort setting, start with a
74°F (23°C) temperature setting and allow
about 20 minutes for the system to regulate.
Use the driver’s or passenger’s temperature
buttons to adjust the temperature setting as
necessary. If you choose the temperature
setting of 60°F (15°C), the system will remain at
the maximum cooling setting. If you choose the
temperature setting of 90°F (32°C), the system
will remain at the maximum heat setting.
Choosing either maximum setting will not cause
the vehicle to heat or cool any faster.
Be careful not to cover the sensor located on the
top of the instrument panel near the windshield.
This sensor regulates air temperature based
on sun load and also turns on your headlamps.
To avoid blowing cold air in cold weather, the
system will delay turning on the fan until warm air
is available. The length of delay depends on
the engine coolant temperature. Pressing the fan
switch will override this delay and change the
fan to a selected speed.
215

O(On/Off):Press this button to turn off the
climate control system. Outside air will still enter
the vehicle, and will be directed to the oor.
This direction can be changed by pressing the
mode button. Recirculation can be selected once
you have selected vent or bi-level mode. The
temperature can also be adjusted using either
temperature button. If you adjust the air delivery
mode or temperature settings with the system
off, the display will illuminate briey to show you
the settings and then return off. Press the
on/off button or the up down arrows on the fan
switch, the defrost button, AUTO button, or the air
conditioning button to turn the system on when
it is off.
Manual Operation
You may manually adjust the air delivery mode or
fan speed.
y9 z(Fan):The buttons with the fan symbols
allow you to manually adjust the fan speed.
Press the up arrow to increase fan speed and the
down arrow to decrease fan speed.Pressing one of these buttons when the system is
off will turn the system on. Pressing one of
these buttons when in automatic control will place
the fan under manual control. The fan setting
will remain displayed and the AUTO light will turn
off. The air delivery mode will remain under
automatic control.
yNz(Mode):Press the mode up and down
buttons to manually change the direction of
the airow in your vehicle. Repeatedly press the
button until the desired mode appears on the
display. Pressing one of these buttons when the
system is off will change air delivery mode without
turning the system on. Pressing one of these
buttons when in automatic control will place the
mode under manual control.
The air delivery mode setting will be displayed and
the AUTO light will turn off. The fan will remain
under automatic control.
H(Vent):This setting will deliver air to the
instrument panel outlets.
216

)(Bi-Level):This mode directs half of the air
to the instrument panel outlets and to the oor
outlets. The ow can be divided between vent and
oor outlets depending upon where the knob is
placed between the settings. A little air is directed
towards the windshield and side window outlets.
Cooler air is directed to the upper outlets and
warmer air to the oor outlets.
6(Floor):This mode directs most of the air to
the oor outlets, with some of the air directed
to the windshield, side window outlets, and
second row oor outlets. In this mode, the system
will automatically select outside air.
-(Defog):See “Defogging and Defrosting” later
in this section.
@(Recirculation):Press this button to turn
the recirculation mode on. When the button
is pressed, an indicator light will come on.
This mode keeps outside air from entering the
vehicle. It can be used to reduce outside air and
prevent odors from entering your vehicle.
Recirculation may also help cool the air inside
your vehicle more quickly once the temperature
inside the vehicle is less than the outside
temperature.
The recirculation mode cannot be used with oor,
defrost, or defogging modes. If you try to select
recirculation in one of those modes, the indicator
will ash three times and turn off. 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 the fan speed.
Recirculation mode can be turned off by pressing
the button again, or turning off the engine.
217

Air Conditioning
#
(Air Conditioning):Press this button to turn
the air conditioning (A/C) compressor on and
off. When air conditioning is selected, an indicator
light will come on to let you know that the air
conditioning has been activated.
Pressing this button when the outside temperature
is too cool for air conditioning will make the air
conditioning indicator ash three times and
then turn off to let you know the air conditioning
mode is not available. If the air conditioning
is on and the outside temperature drops below a
temperature which is too cool for air conditioning
to be effective, the air conditioning light will turn off
to let you know the air conditioning mode has
been canceled.
On hot days, open the windows long enough to let
hot inside air escape. This helps to reduce the
time it takes for your vehicle to cool down. It also
helps the system to operate more efficiently.
The air conditioning system removes moisture from
the air, so you may sometimes notice a small
amount of water dripping underneath your vehicle
while idling or after turning off the engine. This
is normal.
Defogging and Defrosting
Fog on the inside of the 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 clear fog or frost from your
windshield.
Use the mode up and down arrows to select the
defog or defrost modes.
-(Defog):The defog mode is used to clear the
windows of fog or moisture and warm the
passengers. This mode directs air to the
windshield, oor outlets, and side window vents.
When you select this mode, the system turns
off recirculation and runs the air conditioning
compressor unless the outside temperature is
close to freezing. The recirculation mode cannot
be selected while in the defog mode. Do not drive
the vehicle until all the windows are clear.
218

Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages
on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that
something is wrong before it becomes serious
enough to cause an expensive repair or
replacement. Paying attention to your warning
lights and gages could also save you or others
from injury.
Warning lights come on when there may be or is
a problem with one of your vehicle’s functions.
As you will see in the details on the next few
pages, some warning lights come on briey when
you start the engine just to let you know they
are working. If you are familiar with this section,
you should not be alarmed when this happens.Gages can indicate when there may be or is a
problem with one of your vehicle’s functions.
Often gages and warning lights work together to
let you know when there is a problem with
your vehicle.
When one of the warning lights comes on and
stays on when you are driving, or when one of the
gages shows there may be a problem, check
the section that tells you what to do about
it. Please follow this manual’s advice. Waiting to
do repairs can be costly – and even dangerous.
So please get to know your warning lights
and gages. They are a big help.
Your vehicle also has a Driver Information Center
(DIC) that works along with warning lights and
gages. SeeDIC Warnings and Messages
on page 254.
224

Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour
(km/h). Your odometer shows how far your vehicle
has been driven, in either miles (used in the
United States) or kilometers (used in Canada).
Trip Odometer
The trip odometer can tell you how far your vehicle
has been driven since you last set the trip odometer
to zero.
Press the reset button, located on the instrument
panel cluster next to the trip odometer display,
to toggle between the trip odometer and the
regular odometer. Holding the reset button for
approximately one second while the trip odometer
is displayed will reset it.
To display the odometer reading with the ignition
off, press the reset button.
Tachometer
Your tachometer displays the engine speed in
revolutions per minute (rpm).
Safety Belt Reminder Light
When the key is turned to RUN or START, a chime
will be provided for several seconds to remind
people to buckle their safety belts. The driver safety
belt light will also be provided and stay on for
several seconds, then it will ash for several more.
You should buckle your seat belt.
This chime and light will
be repeated if the driver
remains unbuckled
and the vehicle
is in motion.
If the driver’s belt is buckled, neither the chime nor
the light will come on.
SeePassenger Sensing System on page 100for
more information.
226

Passenger Safety Belt Reminder
Light
Several seconds after the key is turned to RUN or
START, a chime will sound for several seconds
to remind the front passenger to buckle their safety
belt. The passenger safety belt light will also
come on and stay on for several seconds, then it
will ash for several more.
This chime and light will
be repeated if the
passenger remains
unbuckled and
the vehicle is in motion.
If the passenger’s safety belt is buckled, neither
the chime nor the light will come on.
Airbag Readiness Light
There is an airbag readiness light on the
instrument panel, which shows the airbag symbol.
The system checks the airbag’s electrical
system for malfunctions. The light tells you if there
is an electrical problem. The system check
includes the airbag sensors, the airbag modules,
the wiring and the crash sensing and diagnostic
module. For more information on the airbag
system, seeAirbag System on page 90.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds.
Then the light should go
out. This means the
system is ready.
227

If the airbag readiness light stays on after you
start the vehicle or comes on when you are driving,
your airbag system may not work properly.
Have your vehicle serviced right away.
{CAUTION:
If the airbag readiness light stays on after
you start your vehicle, it means the airbag
system may not be working properly. The
airbags in your vehicle may not inate in
a crash, or they could even inate without
a crash. To help avoid injury to yourself
or others, have your vehicle serviced right
away if the airbag readiness light stays on
after you start your vehicle.
The airbag readiness light should ash for a few
seconds when you turn the ignition key to RUN.
If the light doesn’t come on then, have it xed so it
will be ready to warn you if there is a problem.
Passenger Airbag Status Indicator
Your vehicle has the passenger sensing system.
Your overhead console has a passenger airbag
status indicator.
When the ignition key is turned to RUN or START,
the passenger airbag status indicator will light
ON and OFF, or the symbol for on and off,
for several seconds as a system check. Then,
after several more seconds, the status indicator
will light either ON or OFF, or either the on
or off symbol to let you know the status of the
right front passenger’s frontal airbag.
Passenger
Airbag Status
Indicator – United
StatesPassenger
Airbag Status
Indicator – Canada
228

If, after several seconds, all status indicator lights
remain on, or if there are no lights at all, there
may be a problem with the lights or the passenger
sensing system. See your dealer for service.
{CAUTION:
If the off indicator and the airbag
readiness light ever come on together, it
means that something may be wrong with
the airbag system. If this ever happens,
have the vehicle serviced promptly,
because an adult-size person sitting in the
right front passenger seat may not have
the protection of the frontal airbag. See
Airbag Readiness Light on page 227.
Charging System Light
The charging system
light will come on briey
when you turn on the
ignition, but the
engine is not running,
as a check to show you
it is working.
It should go out once the engine is running.
If it stays on, or comes on while you are driving,
you may have a problem with the charging system.
It could indicate that you have problems with the
generator, the generator drive belt, or another
electrical problem. Have it checked right away.
Driving while this light is on could drain your
battery.
When this light comes on, the DIC will also display
the SERVICE BATTERY NOT CHARGING
SYSTEM message. SeeDIC Warnings and
Messages on page 254for more information.
If you must drive a short distance with the light on,
be certain to turn off all your accessories, such as
the radio and air conditioner, to reduce the drain on
your battery.
230