2008 GMC YUKON DENALI light

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.
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.
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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 5-7. 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.
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.
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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 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 2-34.
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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. 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
This light, under the fuel
gage, will come on briey
when you are starting
the engine. United States
Canada
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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 3-56for 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.
For the displays available using DIC buttons, see “DIC
Operation and Displays (Using DIC Buttons)” later
in this section andDIC Vehicle Customization (With DIC
Buttons) on page 3-64.
For the displays available using the trip odometer reset
stem, see “DIC Operation and Displays (Using Trip
Odometer Reset Stem)” later in this section.
DIC Operation and Displays
(Using DIC Buttons)
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 3-64for more information.
You can also use the trip odometer reset stem to view
some of the DIC displays. See “DIC Operation and
Displays (Using Trip Odometer Reset Stem)” later in this
section.
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DIC Warnings and Messages
Messages are displayed on the 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. Multiple messages may appear one after
another.
Some messages may not require immediate action, but
you can press any of the DIC buttons on the instrument
panel or the trip odometer reset stem on the instrument
panel cluster to acknowledge that you received the
messages and to clear them from the display.
Some messages cannot be cleared from the DIC
display because they are more urgent. These messages
require action before they can be cleared. 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.
CHANGE ENGINE OIL SOON
This message displays when the engine oil needs to be
changed. When you change the engine oil, be sure
to reset the CHANGE ENGINE OIL SOON message.
SeeEngine Oil Life System on page 5-16for information
on how to reset the message. SeeEngine Oil on
page 5-13andScheduled Maintenance on page 6-4for
more information.
CHECK TIRE PRESSURE
This message displays when the pressure in one or
more of the vehicle’s tires needs to be checked.
This message also displays LEFT FRONT, RIGHT
FRONT, LEFT REAR, or RIGHT REAR to indicate which
tire needs to be checked. You can receive more than
one tire pressure message at a time. To read the other
messages that may have been sent at the same
time, press the set/reset button or the trip odometer
reset stem. If a tire pressure message appears on the
DIC, stop as soon as you can. Have the tire pressures
checked and set to those shown on the Tire Loading
Information label. SeeTires on page 5-55,Loading Your
Vehicle on page 4-34, andInflation - Tire Pressure on
page 5-60. The DIC also shows the tire pressure values.
See “DIC Operation and Displays (Using DIC Buttons)”
earlier in this section. If the tire pressure is low, the
low tire pressure warning light comes on. SeeTire
Pressure Light on page 3-41.
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