light GMC YUKON 2005 Repair Manual

If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push or may go closer to the oor. It may
take longer to stop. If the light is still on, have the vehicle
towed for service. SeeTowing Your Vehicle on
page 4-62.
{CAUTION:
Your brake system may not be working
properly if the brake system warning light is
on. Driving with the brake system warning light
on can lead to an accident. If the light is still
on after you have pulled off the road and
stopped carefully, have the vehicle towed for
service.
Anti-Lock Brake System Warning
Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on
for several seconds.
That’s normal. If the light doesn’t come on then, have
it xed so it will be ready to warn you if there is a
problem.
If the light stays on, or comes on when you’re driving,
your vehicle needs service. You will also hear a
chime sound when the light is on steady. If the regular
brake system warning light isn’t on, you still have
brakes, but you don’t have anti-lock brakes. If the
regular brake system warning light is also on you don’t
have anti-lock brakes and there’s a problem with
your regular brakes. In addition to both lights, you will
also hear a chime sound on the rst occurrence of
a problem and each time the vehicle is shut off and
then restarted. SeeBrake System Warning Light
on page 3-43.
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Traction Off Light
If you have the Traction
Assist System, this light
should come on briey
when you turn the ignition
to RUN.
If the light doesn’t come on then, the system may
require service; have it xed so it will be there to warn
you if the system is turned off.
If the light stays on, or comes on when you’re driving,
there may be a problem with your Traction Assist
System and your vehicle may need service. When this
light is on, the system will not limit wheel spin. Adjust
your driving accordingly.
The traction off light may come on for the following
reasons:
If you turn the system off by pressing the TAS
on/off button located to the left of the steering wheel,
the light will come on and stay on. To turn the
system back on, press the button again; the light
should go off.
If you move the shift lever to FIRST (1), the light
will come on and stay on to indicate that the
traction system is off. This is normal operation.
To turn the system back on, move the shift lever
back to a position other than FIRST (1); the
light should go off. SeeTraction Assist System
(TAS) on page 4-8.
The light will come on and stay on if the TAS
automatic engagement feature has been turned off.
To turn the system on, press the TAS off/on
button; the light should go off. To turn the automatic
engagement feature back on, seeTraction Assist
System (TAS) on page 4-8.
If the Traction Assist System is affected by an
anti-lock brake system, TAS or engine-related
problem, the system will turn off and the light will
come on. Have your vehicle serviced.
If the vehicle is driven over an extremely rough road,
the system will turn off and the light will come on. The
light will go off a few seconds after the rough road
conditions go away or when the vehicle comes to a
complete stop. This is normal operation.
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Tire Pressure Light
If your vehicle is equipped
with the Tire Pressure
Monitor system, this light
will come on if the
system detects low tire
pressure.
A CHECK TIRE PRESSURE DIC message will
accompany the light.
This light will also come on for a bulb check when the
vehicle is started.
SeeTire Pressure Monitor System on page 5-65for
more information.
For more information on your tires, seeTires on
page 5-57.
Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition, and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. The check engine light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls may not
work as well, your fuel economy may not be as good,
and your engine may not run as smoothly. This could
lead to costly repairs that may not be covered by
your warranty.
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Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on, as a check to show you it
is working, when the ignition is on and the engine is not
running. If the light does not come on, have it repaired.
This light will also come on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible
If the light stops ashing and remains on steady, see
“If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see “If
the Light Is On Steady” following. If the light is still
ashing, follow the previous steps, and see your dealer
for service as soon as possible.
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If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling the Tank on page 5-8. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-5. Poor fuel quality will
cause your engine not to run as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misring, hesitation
on acceleration, or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to x any
mechanical or electrical problems that may have
developed.
Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this inspection
could prevent you from getting a vehicle registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the check
engine light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your battery
has run down. The diagnostic system is designed to
evaluate critical emission control systems during normal
driving. This may take several days of routine driving.
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Security Light
This light ashes when the
vehicle security system is
activated.
Cruise Control Light
This light comes on
whenever you set your
cruise control.
The light will go out when the cruise control is turned
off. SeeCruise Control on page 3-11for more
information.
Highbeam On Light
This light will come on
when the high-beam
headlamps are in use.
SeeHeadlamp High/Low-Beam Changer on page 3-8.
Four-Wheel-Drive Light
The four-wheel-drive
indicator will light up when
the vehicle is in four-wheel
drive.
SeeFour-Wheel Drive on page 2-27for more
information.
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Tow/Haul Mode Light
This light is displayed
when the Tow/Haul mode
has been activated.
For more information, seeTowing a Trailer on
page 4-67.
Fuel Gage
The fuel gage, when the ignition is on, tells you about
how much fuel you have left in your tank.The gage will rst indicate empty before you are out of
fuel, and you should get more fuel as soon as possible.
When the fuel tank is low, the FUEL LEVEL LOW
message will appear. SeeDriver Information Center
(DIC) on page 3-54.
Here are some situations you may experience with your
fuel gage. None of these indicate a problem with the
fuel gage.
At the gas station, the fuel pump shuts off before
the gage reads full.
It takes a little more or less fuel to ll up than the
fuel gage indicated. For example, the gage may
have indicated the tank was half full, but it actually
took a little more or less than half the tank’s
capacity to ll the tank.
The gage goes back to empty when you turn off the
ignition.
Low Fuel Warning Light
The light next to the fuel gage will come on briey when
you are starting the engine.
This light comes on when the fuel tank is low on fuel.
To turn it off, add fuel to the fuel tank. SeeFuel on
page 5-5.
United StatesCanada
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DIC Warnings and Messages
Warning messages are displayed on the Driver
Information Center (DIC) to notify the driver that the
status of the vehicle has changed and that some action
may be needed by the driver to correct the condition.
If there is more than one message that needs to
be displayed, they will appear one after another. Some
messages may not require immediate action, but
you should press any of the four DIC buttons on the
steering wheel, if equipped, to acknowledge that
you received the messages and clear them from the
display. If your vehicle is not equipped with DIC buttons
on the steering wheel, press the trip odometer reset
stem located on the instrument panel cluster to
acknowledge messages and clear them from the display.
Some messages cannot be cleared from the display
because they are more urgent. These messages require
action before they can be removed from the DIC
display. You should take any messages that appear on
the display seriously and remember that clearing the
messages will only make the messages disappear, not
correct the problem. The following are the possible
messages that can be displayed and some information
about them.
BATTERY NOT CHARGING
On some vehicles, if the battery is not charging during
operation, this message will appear on the DIC.
Driving with this problem could drain your battery.
Have the electrical system checked by your GM dealer
as soon as possible. SeeBattery Warning Light on
page 3-42andVoltmeter Gage on page 3-42.
Pressing any of the four DIC buttons, if equipped, will
acknowledge the message and clear it from the
DIC display. If your vehicle is not equipped with the
four DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
BUCKLE PASSENGER
If your vehicle is equipped with the passenger sensing
system, this message reminds you to buckle the
passenger’s seat belt. SeePassenger Sensing System
on page 1-75.
This message will display and a chime will sound
when the ignition is on, the driver’s seat belt is buckled,
the passenger’s seat belt is unbuckled with the
passenger airbag enabled and the vehicle is in
motion. You should have the passenger buckle their
seat belt.
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This reminder will be repeated if the ignition is on, the
vehicle is in motion, the driver is buckled and the
passenger is still unbuckled and the passenger airbag
is enabled. If the passenger’s seat belt is already
buckled, this message and chime will not come on.
Pressing any of the four DIC buttons, if equipped, will
acknowledge the message and clear it from the
DIC display. If your vehicle is not equipped with the
four DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
BUCKLE SEATBELT
If your vehicle is equipped with the passenger sensing
system, this message reminds you to buckle the
driver’s seat belt. SeePassenger Sensing System on
page 1-75.
This message will display and a chime will sound when
the ignition is on, the driver’s seat belt is unbuckled
and the vehicle is in motion. You should buckle
your seat belt.
If the driver remains unbuckled when the ignition is on
and the vehicle is in motion, the reminder will be
repeated. If the driver’s seat belt is already buckled,
this message and chime will not come on.This message is an additional reminder to the Safety
Belt Reminder Light in the instrument panel cluster. See
Safety Belt Reminder Light on page 3-39.
Pressing any of the four DIC buttons, if equipped, will
acknowledge the message and clear it from the
DIC display. If your vehicle is not equipped with the four
DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
CHANGE ENGINE OIL
This message is displayed when the engine oil needs to
be changed.
When you change the engine oil, be sure to reset the
CHANGE ENGINE OIL message. This message
will clear itself after 10 seconds until the next ignition
cycle or until the message is reset. SeeEngine Oil
on page 5-15andScheduled Maintenance on page 6-4
for more information.
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CHARGING SYSTEM FAILURE
On some vehicles, if there is a problem with the
generator and battery charging system, this message
will appear on the DIC, a chime will sound and the
battery warning light on the instrument panel cluster will
come on. Driving with this problem could drain your
battery. Turn off all unnecessary accessories. Stop and
turn off the vehicle as soon as it is safe to do so.
Have the electrical system checked by your GM dealer
immediately. SeeBattery Warning Light on page 3-42
andVoltmeter Gage on page 3-42for more information.
CHECK OIL LEVEL
If your vehicle is equipped with an oil level sensor and
the oil level in the vehicle is low, this message will
appear on the DIC. Check the oil level and correct it as
necessary. You may need to let the vehicle cool or
warm up and cycle the ignition to be sure this message
will clear. The message will clear itself after 10 seconds,
until the next ignition cycle. Once the problem is
corrected, pressing any of the four DIC buttons, if
equipped, will acknowledge the message and clear it
from the DIC display. If your vehicle is not equipped with
the four DIC buttons, pressing the trip odometer reset
stem will acknowledge the message and clear it from the
DIC display.
CHECK TIRE PRESSURE
If your vehicle is equipped with the Tire Pressure
Monitor System and a low tire pressure is detected in
any of the vehicle’s tires, this message will appear
on the DIC, along with a chime. Pressing any of the four
DIC buttons, if equipped, will acknowledge the
message and clear it from the DIC display. If your
vehicle is not equipped with the four DIC buttons,
pressing the trip odometer reset stem will acknowledge
the message and clear it from the DIC display. It will
appear at each ignition cycle until the tires are inated to
the correct ination pressure.
CHECK WASHER FLUID
If the washer uid level is low, this message will appear
on the DIC. Adding washer uid will clear the message.
SeeWindshield Washer Fluid on page 5-36. Pressing
any of the four DIC buttons, if equipped, will
acknowledge the message and clear it from the DIC
display. If your vehicle is not equipped with the four DIC
buttons, pressing the trip odometer reset stem will
acknowledge the message and clear it from the DIC
display. The message will clear itself after 10 seconds or
until the next ignition cycle.
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