engine GMC YUKON 2009 Service Manual

Antilock Brake System (ABS)
Warning Light
For vehicles with the
Antilock Brake System
(ABS), this light comes on
briey when the engine
is started.
If it does not, have the vehicle serviced by your
dealer/retailer. 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. SeeBrake System Warning Light on
page 3-40.
For vehicles with a Driver Information Center (DIC), see
DIC Warnings and Messages on page 3-64for all
brake related DIC messages.
StabiliTrak®Indicator Light
For vehicles with the
StabiliTrak®system, this
light comes on briey while
starting the engine.
If it does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally the
indicator light then goes off.
If the light comes on and stays on while driving, there
could be a problem with the StabiliTrak
®system and the
vehicle might need service. When this warning light is
on, the StabiliTrak
®system is off and does not limit
wheel spin.
The light ashes if the system is active and is working
to assist the driver with directional control of the
vehicle in difficult driving conditions.
SeeStabiliTrak
®System on page 4-6for more
information.
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Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard the vehicle is
working. During a majority of the operation, the gage
reads 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 5-35.
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
Tire Pressure Light
For vehicles with a tire
pressure light, this light
comes on briey when
the engine is started and
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 signicantly
underinated.
A tire pressure message in the Driver Information
Center (DIC), can accompany the light. SeeDIC
Warnings and Messages on page 3-64for more
information. Stop and check the tires as soon as it is
safe to do so. If a tire is underinated, inate to the
proper pressure. SeeTires on page 5-62for more
information. United StatesCanada
3-43

When the Light Flashes First and Then is
On Steady
This indicates that there could be a problem with the Tire
Pressure Monitor System. The light ashes 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 System on page 5-72
for 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/retailer.If the check engine light comes on and stays on, while
the engine is running, this indicates that there is an
OBD II problem and service is required.
Malfunctions often are indicated by the system before
any problem is apparent. Being aware of the light
can prevent more serious damage to the vehicle. This
system assists the service technician in correctly
diagnosing any malfunction.
Notice:If the vehicle is continually driven with this
light on, after a while, the emission controls
might not work as well, the 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 the vehicle warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of the
vehicle or the replacement of the original tires with
other than those of the same Tire Performance
Criteria (TPC) can affect the vehicle’s emission
controls and can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by the vehicle warranty. This
could also result in a failure to pass a required
Emission Inspection/Maintenance test. See
Accessories and Modifications on page 5-3.
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This light 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 the vehicle.
Diagnosis and service might be required.
To prevent more serious damage to the vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid steep uphill grades.
If towing a trailer, reduce the amount of cargo being
hauled as soon as it is possible.
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
key off, wait at least 10 seconds, and restart the engine.
If the light is still ashing, follow the previous steps and
see your dealer/retailer for service as soon as possible.
Light On Steady:An emission control system
malfunction has been detected on the vehicle. Diagnosis
and service might be required.An emission system malfunction might be corrected by
doing the following:
Make sure the fuel cap is fully installed. 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.
If the vehicle has been driven through a deep puddle
of water, the 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.
Make sure to fuel the vehicle with quality fuel. Poor
fuel quality causes the engine not to run as efficiently
as designed and can cause: stalling after start-up,
stalling when the vehicle is changed into gear,
misring, hesitation on acceleration, or stumbling on
acceleration. These conditions might go away once
the engine is warmed up.
If one or more of these conditions occurs, change the
fuel brand used. It will require at least one full tank of
the proper fuel to turn the light off.
SeeGasoline Octane on page 5-5.
3-45

If none of the above have made the light turn off, your
dealer/retailer can check the vehicle. The 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 the vehicle. Failure to pass this inspection
could prevent getting a vehicle registration.
Here are some things to know to help the vehicle pass
an inspection:
The vehicle will not pass this inspection if the check
engine light is on with the engine running, or if the
key is in ON/RUN and the light is not on.
The vehicle will not pass this inspection if the OBD II
(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 the battery has recently been replaced or if the
battery has run down. The diagnostic system is
designed to evaluate critical emission controlsystems during normal driving. This can take several
days of routine driving. If this has been done and the
vehicle still does not pass the inspection for lack of
OBD II system readiness, your dealer/retailer 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).United States
Canada
3-46

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 appears in the Driver Information
Center (DIC). SeeDIC Warnings and Messages
on page 3-64andEngine 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 the oil as soon
as possible.
{CAUTION:
Do not keep driving if the oil pressure is low. The
engine can become so hot that it catches re.
Someone could be burned. Check the oil as soon
as possible and have the vehicle serviced.
Notice:Lack of proper engine oil maintenance can
damage the engine. The repairs would not be
covered by the vehicle warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
3-47

Oil Pressure Light
{CAUTION:
Do not keep driving if the oil pressure is low. The
engine can become so hot that it catches re.
Someone could be burned. Check the oil as soon
as possible and have the vehicle serviced.
Notice:Lack of proper engine oil maintenance can
damage the engine. The repairs would not be
covered by the vehicle warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.This light comes on briey while starting the engine. If it
does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally the
indicator light then goes off.
If the light comes on and stays on, it means that oil is
not owing through the engine properly. The vehicle
could be low on oil and it 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 2-21.
3-48

Low Fuel Warning Light
This light, under the fuel
gage, comes on briey
while the engine is being
started.
This light and a chime comes on when the fuel tank is low
on fuel. The Driver Information Center also displays a
“FUEL LEVEL LOW” message. SeeDIC Warnings and
Messages on page 3-64for more information. When fuel
is added this light and message should go off. If it does
not, have the vehicle serviced by your dealer/retailer.
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 3-74for 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.
3-51

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 3-74for 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. The
compass and outside air temperature will also be shown
in the display. The temperature will be shown in °F or °C
depending on the units selected.
T(Vehicle Information):Press this button to display
the oil life, units, side blind zone system on/off, tire
pressure readings for vehicles with the Tire Pressure
Monitor System (TPMS), trailer brake gain and output
information for vehicles with the Integrated Trailer Brake
Control (ITBC) system, engine hours, Remote Keyless
Entry (RKE) transmitter programming, compass zone
setting, and compass recalibration.
3-52

Transmission Temperature
Press the trip/fuel button until TRANS TEMP displays.
This display shows the temperature of the automatic
transmission uid in either degrees Fahrenheit (°F) or
degrees Celsius (°C).
Blank Display
This display shows no information.
Vehicle Information Menu Items
T
(Vehicle Information):Press this button to scroll
through the following menu items:
Oil Life
Press the vehicle information button until OIL LIFE
REMAINING displays. This display shows an estimate of
the oil’s remaining useful life. If you see 99% OIL LIFE
REMAINING on the display, that means 99% of the
current oil life remains. The engine oil life system will alert
you to change the oil on a schedule consistent with your
driving conditions.
When the remaining oil life is low, the CHANGE ENGINE
OIL SOON message will appear on the display. See
“CHANGE ENGINE OIL SOON” underDIC Warnings
and Messages on page 3-64. You should change the
oil as soon as you can. SeeEngine Oil on page 5-15.In addition to the engine oil life system monitoring the oil
life, additional maintenance is recommended in the
Maintenance Schedule in this manual. SeeScheduled
Maintenance on page 6-4for more information.
Remember, you must reset the OIL LIFE display
yourself after each oil change. It will not reset itself.
Also, be careful not to reset the OIL LIFE display
accidentally at any time other than when the oil has just
been changed. It cannot be reset accurately until the
next oil change. To reset the engine oil life system, see
Engine Oil Life System on page 5-18.
Side Blind Zone Alert
If your vehicle has the Side Blind Zone Alert (SBZA)
system, this display allows the system to be turned on or
off. Once in this display, press the set/reset button to
select between ON or OFF. If you choose ON, the
system will be turned on. If you choose OFF, the system
will be turned off. When the SBZA system is turned
off, the DIC will display the SIDE BLIND ZONE ALERT
SYSTEM OFF message as a reminder that the
system has been turned off. SeeDIC Warnings and
Messages on page 3-64andSide Blind Zone Alert
(SBZA) on page 2-56for more information.
3-55