ignition GMC YUKON 2010 Service Manual

Fog Lamps
For vehicles with fog lamps, the control is located next
to the exterior lamps control on the instrument panel, to
the left of the steering column.
The ignition must be in the ON/RUN position for the fog
lamps to come on.
#(Fog Lamps):Press to turn the fog lamps on or off.
A light will come on in the instrument panel cluster.
When the fog lamps are turned on, the parking lamps
automatically turn on.
When the headlamps are changed to high-beam, the
fog lamps also go off. When the high-beam headlamps
are turned off, the fog lamps will come on again.
Some localities have laws that require the headlamps to
be on along with the fog lamps.
Auxiliary Roof-Mounted Lamp
If the vehicle has this feature, this button includes wiring
provisions for a dealer or a qualified service center to
install an auxiliary roof lamp.
This button is located on
the overhead console.
When the wiring is connected to an auxiliary roof
mounted lamp, pressing the bottom of the button will
activate the lamp and illuminate an indicator light at the
bottom of this button. Pressing the top of the button will
turn off the roof mounted lamp and indicator.
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Entry Lighting
The vehicle has an illuminated entry feature.
When the doors are opened, the dome lamps will
come on if the dome override button is in the extended
position. If the dome override button is pressed in, the
lamps will not come on.
Exit Lighting
The interior lamps come on when the key is removed
from the ignition. They turn off automatically in
20 seconds. The lights do not come on if the dome
override button is pressed in.
Reading Lamps
For vehicles with reading lamps they are located on the
overhead console.
To turn on the reading lamps, press the button located
next to each lamp. To turn them off, press the button
again.
The vehicle may also have reading lamps in other
locations. To turn the lamps on or off, press the button
located next to the lamp.
The lamps are fixed and cannot be adjusted.
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 bring the charge back up.
When the state of charge is high, the voltage is lowered
slightly to prevent overcharging. If the vehicle has a
voltmeter gauge 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 are on, such as: 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.
4-15

EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator's output
and the vehicle's electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands
of some accessories.
Normally, these actions occur in steps or levels,
without being noticeable. In rare cases at the highest
levels of corrective action, this action may be noticeable
to the driver. If so, a Driver Information Center (DIC)
message might be displayed, such as BATTERY
SAVER ACTIVE, BATTERY VOLTAGE LOW, orLOW BATTERY. If this message is displayed, it is
recommended that the driver reduce the electrical
loads as much as possible. See DIC Warnings and
Messages on page 4‑61.
Battery Run-Down Protection
This feature shuts off the dome, and reading lamps
if they are left on for more than 10 minutes when
the ignition is off. This will keep the battery from
running down.
Accessory Power Outlet(s)
Accessory power outlets can be used to connect
auxiliary electrical equipment, such as a cellular
telephone.
There are two under the climate controls, one inside the
center floor console, one on the rear of the center floor
console and one accessory power outlet in the rear
cargo area on the passenger side.
To use an accessory power outlet, remove the
protective cap. When not in use, always cover the
accessory power outlet with the protective cap.
The accessory power outlets are powered, even with
the ignition off. Continuing to use accessory power
outlets while the ignition is in LOCK/OFF may cause
the vehicle's battery to run down.
Notice: If electrical devices are left plugged into
a power outlet, the battery may drain causing the
vehicle not to start or damage to the battery.
This would not be covered by the vehicle warranty.
Always unplug all electrical devices when turning
off the vehicle.
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#(Air Conditioning):Press to turn the air
conditioning (A/C) compressor on and off. An indicator
light comes on to show that the air conditioning is on.
If this button is pressed when the air conditioning
compressor is unavailable, the indicator flashes three
times and then turns off. 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 turns off to show that 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 the vehicle to cool down. It also helps the system to
operate more efficiently.
The air conditioning system removes moisture from
the air, so a small amount of water might drip under
the vehicle while idling or after turning off the engine.
This is normal.@(Recirculation): Press to turn the recirculation
mode on or off. An indicator light comes on to show that
the recirculation is on.
This mode recirculates and helps to quickly cool the
air inside the vehicle. It can be used to help prevent
outside air and odors from entering the vehicle.
The recirculation mode cannot be used with floor, defog,
or defrost modes. If recirculation is selected with one
of those modes, the indicator light flashes three times
and then turns off. The air conditioning compressor
also comes 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.
The recirculation mode can also be turned off by turning
off the ignition.
REAR: For vehicles with the rear heat and air
conditioning controls. Press to turn the rear climate
control system on or off. See Rear Air Conditioning and
Heating System and Electronic Climate Controls
on
page 4‑28.
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Speedometer and Odometer
The speedometer shows the vehicle's speed in both
kilometers per hour (km/h) and miles per hour (mph).
The odometer shows how far the vehicle has been
driven, in either kilometers (used in Canada) or miles
(used in the United States).
Trip Odometer
The trip odometer can show how far the vehicle has
been driven since the trip odometer was last set 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 resets it.
To display the odometer reading with the ignition off,
press the reset button.
Tachometer
The tachometer displays the engine speed in
revolutions per minute (rpm).
Safety Belt Reminders
Driver Safety Belt Reminder Light
When the engine is started, a chime sounds for several
seconds to remind a driver to fasten the safety belt,
unless the driver safety belt is already buckled.
The safety belt light
flashes for several
seconds, then comes on
solid for several more.
This chime and light sequence are repeated if the driver
remains unbuckled and the vehicle is in motion. If the
driver safety belt is already buckled, neither the chime
nor the light comes on.
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If the word ON or the on symbol is lit on the passenger
airbag status indicator, it means that the right front
passenger frontal airbag is enabled (may inflate).
If the word OFF or the off symbol is lit on the airbag
status indicator, it means that the passenger sensing
system has turned off the right front passenger frontal
airbag.
If, after several seconds, both 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.
{WARNING:
If the airbag readiness light ever comes on and
stays on, it means that something may be wrong
with the airbag system. To help avoid injury to
yourself or others, have the vehicle serviced right
away. SeeAirbag Readiness Light
on page 4‑32
for more information, including important safety
information.
Charging System Light
This light comes on briefly
when the ignition key is
turned to START, but the
engine is not running,
as a check to show it is
working.
If it does not, have the vehicle serviced by your dealer.
The light should go out once the engine starts. If it stays
on, or comes on while driving, there could be a problem
with the charging system. A charging system message
in the Driver Information Center (DIC) can also appear.
See DIC Warnings and Messages
on page 4‑61for
more information. This light could indicate that there are
problems with a generator drive belt, or that there is an
electrical problem. Have it checked right away. If the
vehicle must be driven a short distance with the light
on, turn off accessories, such as the radio and air
conditioner.
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Voltmeter Gauge
When the engine is not
running, but the ignition is
on, this gauge shows the
battery's state of charge
in DC volts.
When the engine is running, the gauge shows the
condition of the charging system. The charging system
regulates voltage based on the state of the battery for
improved fuel economy and battery life. The gauge may
transition from a higher to lower or a lower to higher
reading, this is normal. Readings between the low
and high warning zones indicate the normal operating
range. The gauge may also read low during the fuel
economy mode, this is normal. Readings in the low warning zone may occur when a
large number of electrical accessories are operating
in the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power at
engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create full power. If there
is a problem with the battery charging system, this light
will come on or the SERVICE BATTERY CHARGING
SYSTEM DIC message will display. See
DIC Warnings
and Messages
on page 4‑61and Charging System
Lighton page 4‑34for more information.
4-35

Brake System Warning Light
With the ignition on, the brake system warning light
comes on when the parking brake is set. If the vehicle
is driven with the parking brake engaged, a chime
sounds when the vehicle speed is greater than
8 km/h (5 mph).
The vehicle's hydraulic brake system is divided into two
parts. If one part is not working, the other part can still
work and stop the vehicle. For good braking, both parts
need to be working well.
If the warning light comes on and a chime sounds there
could be a brake problem. Have the brake system
inspected right away.
This light can also come on due to low brake fluid.
SeeBrakes
on page 6‑42for more information.
United StatesCanada
This light comes on briefly when the ignition key is
turned to ON/RUN. If it does not come on then, have it
fixed so it is ready to warn if there is a problem.
{WARNING:
The brake system might not be working properly if
the brake system warning light is on. Driving with
the brake system warning light on can lead to a
crash. If the light is still on after the vehicle has
been pulled off the road and carefully stopped,
have the vehicle towed for service.
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If the light comes on while driving, pull off the road and
stop carefully. The pedal might be harder to push or
might go closer to the floor. It can take longer to stop.
If the light is still on, have the vehicle towed for service.
SeeTowing Your Vehicle on page 5‑41.
Antilock Brake System (ABS)
Warning Light
For vehicles with the
Antilock Brake System
(ABS), this light comes on
briefly when the engine is
started.
If it does not, have the vehicle serviced by your dealer.
If the system is working normally the indicator light then
goes off. If the ABS light stays on, turn the ignition off. If the light
comes on while driving, stop as soon as it is safely
possible and turn the ignition off. Then start the engine
again to reset the system. If the ABS light stays on,
or comes on again while driving, the vehicle needs
service. If the regular brake system warning light is not
on, the vehicle still has brakes, but not antilock brakes.
If the regular brake system warning light is also on, the
vehicle does not have antilock brakes and there is a
problem with the regular brakes. See
Brake System
Warning Light on page 4‑36.
For vehicles with a Driver Information Center (DIC), see
DIC Warnings and Messages
on page 4‑61for all
brake related DIC messages.
4-37

Tire Pressure Light
For vehicles with a tire
pressure monitoring
system, this light comes
on briefly when the engine
is started. It provides
information about tire
pressures and the Tire
Pressure Monitoring
System.
When the Light is On Steady
This indicates that one or more of the tires is
significantly underinflated.
A tire pressure message in the Driver Information
Center (DIC), can accompany the light. SeeDriver
Information Center (DIC)
on page 4‑47for more
information. Stop and check the tires as soon as it
is safe to do so. If underinflated, inflate to the proper
pressure. See Inflation - Tire Pressure
on page 6‑72for more information.
When the Light Flashes First and Then is
On Steady
This indicates that there may be a problem with the Tire
Pressure Monitor System. The light flashes for about a
minute and stays on steady for the remainder of the
ignition cycle. This sequence repeats with every ignition
cycle. SeeTire Pressure Monitor Operation
on
page 6‑75for more information.
Malfunction Indicator Lamp
Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation
of the fuel, ignition, and emission control systems.
It ensures that emissions are at acceptable levels for
the life of the vehicle, helping to produce a cleaner
environment.
This light should come on
when the ignition is on,
but the engine is not
running, as a check to
show it is working. If it
does not, have the vehicle
serviced by your dealer.
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