light GMC YUKON 2006 Repair Manual

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’s frontal
airbag. SeePassenger Sensing System on page 1-82
for more on this, including important safety information.
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. SeeAirbag
Readiness Light on page 3-38.
Battery Warning Light
If this light is displayed
when the engine is
running, you may have
a problem with your
charging system.
The battery display will also stay on while the key is in
RUN until the engine is started.
If the light stays on after starting the engine it could
indicate a problem with the generator drive belt, or some
other charging system problem. Have it checked right
away. Driving with this light displayed could drain
your battery.
If you must drive a short distance with this light
displayed, it helps to turn off all your accessories, such
as the radio and the air conditioner.
3-40

Brake System Warning Light
With the ignition on, the brake system warning light will
ash when you set the parking brake. The light will ash if
the parking brake doesn’t release fully. If you try to drive
with the parking brake engaged, a chime will sound when
the vehicle speed is greater than 3 mph (5 km/h).
Your vehicle’s hydraulic brake system is divided into
two parts. If one part isn’t working, the other part can still
work and stop you. For good braking, though, you
need both parts working well.
If the warning light comes on and a chime sounds there
could be a brake problem. Have your brake system
inspected right away.
This light should come on briey when you turn the
ignition key to RUN. If it doesn’t come on then, have it
xed so it will be ready to warn you if there’s a problem.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 4-56.
{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.
United States
Canada
3-42

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 3-42.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210°F (100°C) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
uctuate and approach the 250°F (122°C) mark. If the
gage reaches the 260°F (125°C) mark, it indicates
that the cooling system is working beyond its capacity.
SeeEngine Overheating on page 5-28.
United StatesCanada
3-43

Notice:If you drive your vehicle with the
transmission temperature gage above normal
operating range, you can damage the transmission.
This could lead to costly repairs that would not
be covered by your warranty. Do not drive your
vehicle while the transmission temperature gage
reading is above normal. See your dealer for service.
The following situations can cause the transmission to
operate at higher temperatures:
Towing a trailer
Hot outside air temperatures
Hauling a large or heavy load
Vehicle overloading
Low transmission uid level
High transmission uid level
Restricted air ow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, seeScheduled Maintenance
on page 6-4for the proper transmission maintenance
intervals.
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 briey as you start the
engine.
SeeTire Pressure Monitor System on page 5-64for
more information.
For more information on your tires, seeTires on
page 5-57.
3-45

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.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. SeeAccessories
and Modifications on page 5-3.
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.
3-46

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.
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.
SeeGasoline 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.
3-47

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. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your GM dealer can prepare the
vehicle for inspection.
Oil Pressure Gage
The oil pressure gage shows the engine oil pressure
in psi (pounds per square inch) when the engine
is running. Canadian vehicles indicate pressure in
kPa (kilopascals).
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.United States
Canada
3-48

A reading in the low pressure zone may be caused by a
dangerously low oil level or some other problem
causing low oil pressure. Check your oil as soon as
possible. See “OIL PRESSURE LOW” underDIC
Warnings and Messages on page 3-56andEngine Oil
on page 5-15.
{CAUTION:
Do not keep driving if the oil pressure is low.
If you do, your engine can become so hot that
it catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
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.
3-49

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 2-26for more
information.
Tow/Haul Mode Light
This light is displayed
when the Tow/Haul mode
has been activated.
For more information, seeTowing a Trailer on
page 4-60.
3-50

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. SeeDIC Warnings and Messages
on page 3-56.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 5-4. United States
Canada
3-51