check engine GMC YUKON 2012 User Guide

Black plate (27,1)GMC Yukon/Yukon XL Owner Manual - 2012
Instruments and Controls 5-27
Engine Oil Pressure Light
{WARNING
Do not keep driving if the oil
pressure is low. The engine can
become so hot that it catches fire.
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 for changing engine oil.
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your dealer. 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 flowing through
the engine properly. The vehicle
could be low on oil and it might
have some other system problem.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Low Fuel Warning Light
This light, under the fuel gauge,
comes on briefly while the engine is
being started.
This light and a chime come on
when the fuel tank is low on fuel.
The Driver Information Center also
displays a FUEL LEVEL LOW
message. See
Fuel System
Messages on page 5‑41 for more
information. When fuel is added this
light and message should go off.
If they do not, have the vehicle
serviced by your dealer.
Security Light
The security light should come on
briefly as the engine is started. If the
system is working normally, the
indicator light turns off. If it does not
come on, have the vehicle serviced
by your dealer.
If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system.

Black plate (39,1)GMC Yukon/Yukon XL Owner Manual - 2012
Instruments and Controls 5-39
See“Integrated Trailer Brake
Control System” underTowing
Equipment on page 9‑76 for more
information.
Door Ajar Messages
DRIVER DOOR OPEN
This message displays and a chime
sounds if the driver door is not fully
closed and the vehicle is shifted out
of P (Park). Stop and turn off the
vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
HOOD OPEN
This message displays and a chime
sounds if the hood is not fully
closed. Stop and turn off the
vehicle, check the hood for
obstructions, and close the hood
again. Check to see if the message
still appears on the DIC.
LEFT REAR DOOR OPEN
This message displays and a chime
sounds if the driver side rear door is
not fully closed and the vehicle is
shifted out of P (Park). Stop and turn
off the vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
PASSENGER DOOR OPEN
This message displays and a chime
sounds if the front passenger door
is not fully closed and the vehicle is
shifted out of P (Park). Stop and turn
off the vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
REAR ACCESS OPEN
This message displays and a chime
sounds if the liftgate or liftglass is
open while the ignition is in ON/
RUN. Turn off the vehicle and check
the liftgate and liftglass. Restart the
vehicle and check for the message
on the DIC display.
RIGHT REAR DOOR OPEN
This message displays and a chime
sounds if the passenger side rear
door is not fully closed and the
vehicle is shifted out of P (Park).
Stop and turn off the vehicle, check
the door for obstructions, and close
the door again. Check to see if the
message still appears on the DIC.
Engine Cooling System
Messages
ENGINE HOT A/C (Air
Conditioning) TURNED OFF
This message displays when the
engine coolant becomes hotter than
the normal operating temperature.
See Engine Coolant Temperature
Gauge on page 5‑16. To avoid
added strain on a hot engine, the air
conditioning compressor
automatically turns off. When the
coolant temperature returns to
normal, the air conditioning
compressor turns back on. You can
continue to drive your vehicle.

Black plate (41,1)GMC Yukon/Yukon XL Owner Manual - 2012
Instruments and Controls 5-41
cause of the low oil pressure is
corrected. SeeEngine Oil on
page 10‑8 for more information.
This message displays if low oil
pressure levels occur. Stop the
vehicle as soon as safely possible
and do not operate it until the cause
of the low oil pressure has been
corrected. Check the oil as soon as
possible and have the vehicle
serviced by your dealer. See Engine
Oil on page 10‑8.
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays and a chime
sounds when the cooling system
temperature gets too hot and the
engine further enters the engine
coolant protection mode. See
Engine Overheating on page 10‑21
for further information.
This message also displays when
the engine power is reduced.
Reduced engine power can affect
the vehicle's ability to accelerate. If this message is on, but there
is no reduction in performance,
proceed to your destination. The
performance may be reduced the
next time the vehicle is driven. The
vehicle may be driven at a reduced
speed while this message is on, but
acceleration and speed may be
reduced. Anytime this message
stays on, the vehicle should be
taken to your dealer for service as
soon as possible.
Fuel System Messages
FUEL LEVEL LOW
This message displays and a chime
sounds if the fuel level is low. Refuel
as soon as possible. See
Fuel
Gauge on page 5‑14 andFuel on
page 9‑61 for more information.
TIGHTEN GAS CAP
This message may display along
with the check engine light on the
instrument panel cluster if the fuel cap is not tightened properly. See
Malfunction Indicator Lamp on
page 5‑21. Reinstall the fuel cap
fully. See
Filling the Tank on
page 9‑65. 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 this light and message off.
Key and Lock Messages
REPLACE BATTERY IN
REMOTE KEY
This message displays if a Remote
Keyless Entry (RKE) transmitter
battery is low. The battery needs to
be replaced in the transmitter. See
“Battery Replacement” under
Remote Keyless Entry (RKE)
System Operation on page 2‑3.

Black plate (44,1)GMC Yukon/Yukon XL Owner Manual - 2012
5-44 Instruments and Controls
page 9‑15. To turn the StabiliTrak
system on or off, seeStabiliTrak®
System on page 9‑46.
STABILITRAK OFF may also
display when the stability control
has been automatically disabled.
There are several conditions that
can cause this message to appear.
.One condition is overheating,
which could occur if StabiliTrak
activates continuously for an
extended period of time.
.The message also displays if the
brake system warning light is on.
SeeBrake System Warning
Light on page 5‑23.
.The message could display if the
stability system takes longer
than usual to complete its
diagnostic checks due to driving
conditions.
.The message displays if an
engine or vehicle related
problem has been detected and
the vehicle needs service. See
your dealer. The message turns off as soon as
the conditions that caused the
message to be displayed are no
longer present.
Airbag System Messages
SERVICE AIR BAG
This message displays if there is a
problem with the airbag system.
Have your dealer inspect the
system for problems. See
Airbag
Readiness Light on page 5‑18 and
Airbag System on page 3‑30 for
more information.
Anti-theft Alarm System
Messages
SERVICE THEFT DETERRENT
SYSTEM
This message displays when there
is a problem with the theft-deterrent
system. The vehicle may or may not
restart so you may want to take the
vehicle to your dealer before turning off the engine. See
Immobilizer
Operation on page 2‑15 for more
information.
Tire Messages
SERVICE TIRE MONITOR
SYSTEM
On vehicles with the Tire Pressure
Monitor System (TPMS), this
message displays if a part on the
TPMS is not working properly. The
tire pressure light also flashes and
then remains on during the same
ignition cycle. See Tire Pressure
Light on page 5‑26. Several
conditions may cause this message
to appear. See Tire Pressure
Monitor Operation on page 10‑59 for
more information. If the warning
comes on and stays on, there may
be a problem with the TPMS. See
your dealer.
TIRE LEARNING ACTIVE
On vehicles with the Tire Pressure
Monitor System (TPMS), this
message displays when the TPMS

Black plate (45,1)GMC Yukon/Yukon XL Owner Manual - 2012
Instruments and Controls 5-45
is re-learning the tire positions on
your vehicle. The tire positions must
be re-learned after rotating the tires
or after replacing a tire or sensor.
SeeTire Inspection on page 10‑62,
Tire Rotation on page 10‑62, Tire
Pressure Monitor System on
page 10‑58, and Tire Pressure on
page 10‑56 for more information.
TIRE LOW ADD AIR TO TIRE
On vehicles with the Tire Pressure
Monitor System (TPMS), this
message displays when the
pressure in one or more of the
vehicle's tires needs to be checked.
This message also displays LEFT
FRT (left front), RIGHT FRT (right
front), LEFT RR (left rear),
or RIGHT RR (right rear) to indicate
the location of the low tire. The low
tire pressure warning light will also
come on. See Tire Pressure Light
on page 5‑26. 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.
See
Tires on page 10‑48, Vehicle
Load Limits on page 9‑16, and Tire
Pressure on page 10‑56. The DIC
also shows the tire pressure values.
See “DIC Operation and Displays
(With DIC Buttons)” earlier in this
section.
Transmission Messages
SERVICE 4 WHEEL DRIVE
This message displays if a problem
occurs with the four-wheel-drive
system. If this message appears,
stop as soon as possible and turn
off the vehicle. Make sure the key is
in the LOCK/OFF position for at
least one minute and then restart
the vehicle and check for the
message on the DIC display. If the message is still displayed or
appears again when you begin
driving, the four-wheel-drive system
needs service. See your dealer.
TRANSMISSION HOT IDLE
ENGINE
Notice:
If you drive the vehicle
while the transmission fluid is
overheating and the transmission
temperature warning is displayed
on the instrument panel cluster
and/or DIC, you can damage the
transmission. This could lead to
costly repairs that would not be
covered by the warranty. Do not
drive the vehicle with overheated
transmission fluid or while the
transmission temperature
warning is displayed.
This message displays along with a
sound if the transmission fluid in the
vehicle gets hot. Driving with the
transmission fluid temperature high
can cause damage to the vehicle.
Stop the vehicle and let it idle to
allow the transmission to cool.

Black plate (6,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-6 Driving and Operating
.Try to avoid sudden steering,
acceleration, or braking,
including reducing vehicle speed
by shifting to a lower gear. Any
sudden changes could cause
the tires to slide.
Remember: Antilock brakes help
avoid only the braking skid.
Off-Road Driving
Four-wheel-drive vehicles can be
used for off-road driving. Vehicles
without four-wheel drive and
vehicles not equipped with All
Terrain (AT) or On-Off Road (OOR)
tires must not be driven off-road
except on a level, solid surface. To
contact the tire manufacturer for
more information about the original
equipment tires, see the Limited
Warranty and Owner Assistance
Information manual. Controlling the vehicle is the key to
successful off-road driving. One of
the best ways to control the vehicle
is to control the speed.
{WARNING
When driving off-road, bouncing
and quick changes in direction
can easily throw you out of
position. This could cause you to
lose control and crash. You and
your passengers should always
wear safety belts.
Before Driving Off-Road
.Have all necessary maintenance
and service work completed.
.Fuel the vehicle, fill fluid levels,
and check inflation pressure in
all tires, including the spare,
if equipped.
.Read all the information about
four-wheel-drive vehicles in this
manual.
.Make sure all underbody
shields, if equipped, are properly
attached.
.Know the local laws that apply to
off-road driving.
To gain more ground clearance if
needed, it may be necessary to
remove the front fascia lower
air dam.
Notice: Operating the vehicle for
extended periods without the
front fascia lower air dam
installed can cause improper air
flow to the engine. Re‐attach the
front fascia air dam after off-road
driving.

Black plate (13,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-13
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{WARNING
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.
{WARNING
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will have
to do all the work of slowing down
and they could get so hot that
they would not work well. You
would then have poor braking or
even none going down a hill. You
could crash. Always have the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
.Be alert on top of hills,
something could be in your lane
(stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.
Wet ice can occur at about 0°C
(32°F) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick, so there is even less
traction.

Black plate (14,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-14 Driving and Operating
Try not to break the fragile traction.
If you accelerate too fast, the drive
wheels will spin and polish the
surface under the tires even more.
TheAntilock Brake System (ABS)
on page 9‑44 improves vehicle
stability during hard stops on
slippery roads, but apply the brakes
sooner than when on dry pavement.
Allow greater following distance on
any slippery road and watch for
slippery spots. Icy patches can
occur on otherwise clear roads in
shaded areas. The surface of a
curve or an overpass can remain icy
when the surrounding roads are
clear. Avoid sudden steering
maneuvers and braking while
on ice.
Turn off cruise control on slippery
surfaces.Blizzard Conditions
Being stuck in snow can be a
serious situation. Stay with the
vehicle unless there is help nearby.
If possible, use the Roadside
Assistance Program on page 13‑5.
To get help and keep everyone in
the vehicle safe:
.Turn on the hazard warning
flashers.
.Tie a red cloth to an outside
mirror.
{WARNING
Snow can trap engine exhaust
under the vehicle. This may
cause exhaust gases to get
inside. Engine exhaust contains
carbon monoxide (CO) which
cannot be seen or smelled. It can
cause unconsciousness and even
death.
(Continued)
WARNING (Continued)
If the vehicle is stuck in the snow:
.Clear away snow from around
the base of your vehicle,
especially any that is blocking
the exhaust pipe.
.Check again from time to
time to be sure snow does
not collect there.
.Open a window about 5 cm
(2 in) on the side of the
vehicle that is away from the
wind to bring in fresh air.
.Fully open the air outlets on
or under the instrument
panel.
.Adjust the climate control
system to a setting that
circulates the air inside the
vehicle and set the fan speed
to the highest setting. See
“Climate Control Systems” in
the Index.
(Continued)

Black plate (25,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-25
When the Low Fuel warning
lamp is on and the FUEL LEVEL
LOW message is displayed in
the Driver Information Center
(DIC), the Computer‐Controlled
Cranking System is disabled to
prevent possible vehicle
component damage. When this
happens, hold the ignition switch
in the START position to
continue engine cranking.
Notice: Cranking the engine for
long periods of time, by returning
the key to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down. 2. If the engine does not start after
5‐10 seconds, especially in very
cold weather (below −18°C
or 0°F), it could be flooded with
too much gasoline. Try pushing
the accelerator pedal all the way
to the floor and holding it there
as you hold the key in START
for up to a maximum of
15 seconds. Wait at least
15 seconds between each try, to
allow the cranking motor to cool
down. When the engine starts,
let go of the key and accelerator.
If the vehicle starts briefly but
then stops again, repeat these
steps. This clears the extra
gasoline from the engine. Do not
race the engine immediately
after starting it. Operate the
engine and transmission gently
until the oil warms up and
lubricates all moving parts. Notice:
The engine is designed to
work with the electronics in the
vehicle. If you add electrical parts
or accessories, you could change
the way the engine operates.
Before adding electrical
equipment, check with your
dealer. If you do not, the engine
might not perform properly. Any
resulting damage would not be
covered by the vehicle warranty.

Black plate (44,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-44 Driving and Operating
Brakes
Antilock Brake
System (ABS)
This vehicle has the Antilock Brake
System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the engine is started and the
vehicle begins to drive away, ABS
checks itself. A momentary motor or
clicking noise might be heard while
this test is going on, and it might
even be noticed that the brake
pedal moves a little. This is normal.If there is a problem with ABS, this
warning light stays on. SeeAntilock
Brake System (ABS) Warning Light
on page 5‑24.
If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses that the wheels
are slowing down. If one of the
wheels is about to stop rolling, the
computer will separately work the
brakes at each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
the driver steer around the obstacle
while braking hard. As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You might hear the ABS
pump or motor operating and feel
the brake pedal pulsate, but this is
normal.