GMC YUKON 2008 Owner's Manual

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 5-31.
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
Tire Pressure Light
This light comes on briey
when the engine is started.
This light will also come on when one or more of your
tires are signicantly underinated.
A tire pressure message in the Driver Information
Center (DIC), may accompany the light. SeeDIC
Warnings and Messages on page 3-64for more
information.
Stop and check your tires as soon as it is safe to do so.
If underinated, inate to the proper pressure. See
Tires on page 5-64for more information.
If a problem is detected with the Tire Pressure Monitor
System, this light will ash for approximately
60 seconds and then stay on solid for the remainder of
the ignition cycle. SeeTire Pressure Monitor System
on page 5-73for more information. United States
Canada
3-47

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 makes
sure 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 an OBD II
problem and service is
required.
Malfunctions often are indicated by the system before
any problem is apparent. This can 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 a while, the emission controls
might not work as well, your vehicle’s fuel economy
might not be as good, and the engine might not
run as smoothly. This could lead to costly repairs
that might 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 can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.
3-48

This light comes on, as a check to show it is working,
when the ignition is turned ON/RUN but the engine is not
running. If the light does not come on, have it repaired.
This light also comes on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system on
your vehicle. Diagnosis and service might be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
If the Light is Flashing
The following can prevent more serious damage to your
vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid 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 the vehicle.
Turn the ignition 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/retailer
for service as soon as possible.
If the Light Is On Steady
You might 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 5-9. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap allows fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed should
turn the light off.
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Did you just drive through a deep puddle of water?
If so, your vehicle’s electrical system might be wet. The
condition is usually 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 causes
the engine not to run as efficiently as designed. You
might 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 might 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/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that might have developed.Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
might 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 the battery or if the
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This can 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 dealer/retailer can prepare the
vehicle for inspection.
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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.
When the oil pressure reaches the low pressure
zone, the OIL PRESSURE LOW STOP ENGINE
message will appear in the Driver Information Center
(DIC). SeeDIC Warnings and Messages on page 3-64
andEngine Oil on page 5-15for more information.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.
{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.
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information. United States
Canada
3-51

Oil Pressure Light
{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.
This light will come on
briey when you start your
engine. If it does not,
have your vehicle serviced.When the light comes on and stays on, it means that oil
is not owing through your engine properly. You
could be low on oil and you might have some other
system problem.
Security Light
For information regarding
this light and the vehicle’s
security system, see
Content Theft-Deterrent on
page 2-22.
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Fog Lamp Light
The fog lamp light will
come on when the fog
lamps are in use.
The light will go out when the fog lamps are turned off.
SeeFog Lamps on page 3-19for more information.
Cruise Control Light
This light comes on
whenever you set the
cruise control.
The light goes out when the cruise control is turned off.
SeeCruise Control on page 3-13for more information.
Highbeam On Light
This light comes on when
the high-beam headlamps
are in use.
SeeHeadlamp High/Low-Beam Changer on page 3-9
for more information.
Tow/Haul Mode Light
This light comes on when
the Tow/Haul mode has
been activated.
For more information, seeTow/Haul Mode on page 2-37.
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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 in the Driver Information Center
(DIC). SeeDIC Warnings and Messages on page 3-64
for more information.
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.
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information. United States
Canada
3-54

Low Fuel Warning Light
This light, under the fuel
gage, will come on briey
when you are starting
the engine.
This light and a chime will come on when the fuel tank is
low on fuel. There will also be a “FUEL LEVEL LOW”
message on the Driver Information Center, seeDIC
Warnings and Messages on page 3-64for more
information. When you add fuel this light and message
should go off. If it does not, have your vehicle serviced.
Driver Information Center (DIC)
Your vehicle has a Driver Information Center (DIC).
The DIC displays information about your vehicle. It also
displays warning messages if a system problem is
detected.
All messages will appear in the DIC display located
below the tachometer in the instrument panel cluster.
The DIC comes on when the ignition is on. After a short
delay, the DIC will display the information that was
last displayed before the engine was turned off.
If your vehicle has DIC buttons, see “DIC Operation and
Displays (With DIC Buttons)” later in this section and
DIC Vehicle Customization (With DIC Buttons) on
page 3-72for the displays available.
If your vehicle does not have DIC buttons, see “DIC
Operation and Displays (Without DIC Buttons)” later in
this section for the displays available.
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DIC Operation and Displays
(With DIC Buttons)
If your vehicle has DIC buttons, the information below
explains the operation of this system.
The DIC has different displays which can be accessed
by pressing the DIC buttons located on the instrument
panel, next to the steering wheel.
The DIC displays trip, fuel, and vehicle system
information, and warning messages if a system problem
is detected.
The DIC also allows some features to be customized.
SeeDIC Vehicle Customization (With DIC Buttons)
on page 3-72for more information.
If your vehicle has DIC buttons, you can also use the
trip odometer reset stem to view some of the DIC
displays. See “DIC Operation and Displays (Without DIC
Buttons)” later in this section.
DIC Buttons
The buttons are the
trip/fuel, vehicle
information, customization,
and set/reset buttons.
The button functions are
detailed in the following
pages.
3(Trip/Fuel):Press this button to display the
odometer, trip odometer, fuel range, average economy,
fuel used, timer, and transmission temperature.
Some vehicles also display instantaneous economy and
an Active Fuel Management™ indicator.
T(Vehicle Information):Press this button to display
the oil life, units, tire pressure readings, engine hours,
and Remote Keyless Entry (RKE) transmitter
programming.
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