service indicator GMC YUKON 2012 Owner's Guide

Black plate (63,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-63
Fuel Additives
To provide cleaner air, all gasolines
in the United States are now
required to contain additives that
help prevent engine and fuel system
deposits from forming, allowing the
emission control system to work
properly. In most cases, nothing
should have to be added to the fuel.
However, some gasolines contain
only the minimum amount of
additive required to meet U.S.
Environmental Protection Agency
regulations. To help keep fuel
injectors and intake valves clean
and avoid problems due to dirty
injectors or valves, look for gasoline
that is advertised as TOP TIER
Detergent Gasoline. Look for the
TOP TIER label on the fuel pump to
ensure gasoline meets enhanced
detergency standards developed by
the auto companies. A list of
marketers providing TOP TIER
Detergent Gasoline can be found at
www.toptiergas.com.For customers who do not use TOP
TIER Detergent Gasoline regularly,
one bottle of GM Fuel System
Treatment PLUS, added to the fuel
tank at every engine oil change, can
help clean deposits from fuel
injectors and intake valves. GM Fuel
System Treatment PLUS is the only
gasoline additive recommended by
General Motors. It is available at
your dealer.
Gasolines containing oxygenates,
such as ethers and ethanol, and
reformulated gasolines might be
available in your area. We
recommend that you use these
gasolines, if they comply with the
specifications described earlier.
However, E85 (85% ethanol) and
other fuels containing more than
15% ethanol must not be used in
vehicles that were not designed for
those fuels.
Notice:
This vehicle was not
designed for fuel that contains
methanol. Do not use fuel
containing methanol. It can
corrode metal parts in the fuel
system and also damage plastic
and rubber parts. That damage
would not be covered under the
vehicle warranty.
Some gasolines that are not
reformulated for low emissions can
contain an octane-enhancing
additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant
where you buy gasoline whether the
fuel contains MMT. We recommend
against the use of such gasolines.
Fuels containing MMT can reduce
spark plug life and affect emission
control system performance. The
malfunction indicator lamp might
turn on. If this occurs, return to your
dealer for service.

Black plate (64,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-64 Driving and Operating
Fuel E85 (85% Ethanol)
Vehicles that have a FlexFuel badge
and a yellow fuel cap can use either
unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85).
For all other vehicles, use only the
unleaded gasoline described under
Recommended Fuel on page 9‑62.
We encourage the use of E85 in
vehicles that are designed to use it.
The ethanol in E85 is a“renewable”
fuel, meaning it is made from
renewable sources such as corn
and other crops.
Many service stations will not have
an 85% ethanol fuel (E85) pump
available. The U.S. Department of
Energy has an alternative fuels
website (www.afdc.energy.gov/afdc/
locator/stations/) that can help you find E85 fuel. Those stations that do
have E85 should have a label
indicating ethanol content. Do not
use the fuel if the ethanol content is
greater than 85%.
At a minimum, E85 should meet
ASTM Specification D 5798 or
CGSB Specification 3.512. Filling
the tank with fuel mixtures that
do not meet ASTM or CGSB
specifications can affect driveability
and could cause the malfunction
indicator lamp to come on. As the
outside temperature approaches
freezing, ethanol fuel distributors
should supply winter grade ethanol,
the same as with unleaded
gasoline.
It is best not to alternate repeatedly
between gasoline and E85. If you
do switch fuels, it is recommended
that you add as much fuel as
possible
—do not add less than
11 L (3 gal) when refueling. You
should drive the vehicle immediately
after refueling for at least 11 km
(7 mi) to allow the vehicle to adapt
to the change in ethanol
concentration.
E85 has less energy per liter
(gallon) than gasoline, so you will
need to refill the fuel tank more
often when using E85 than when
you are using gasoline. See Filling
the Tank on page 9‑65.
Notice: Some additives are not
compatible with E85 fuel and can
harm the vehicle's fuel system.
Do not add anything to E85.
Damage caused by additives
would not be covered by the
vehicle warranty.

Black plate (21,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-21
4. With the coolant surge tankpressure cap off, start the
engine and let it run until the
upper radiator hose can be felt
getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge tank
until the level reaches the FULL
COLD mark. 5. Replace the pressure cap. Be
sure the pressure cap is
hand-tight and fully seated.
6. Verify coolant level after engine is shut off and the coolant is
cold. If necessary, repeat coolant
fill procedure Steps 1 through 6.
Notice: If the pressure cap is not
tightly installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on your vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑16. In addition, ENGINE OVERHEATED
STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and
an ENGINE POWER IS REDUCED
message comes on in the Driver
Information Center (DIC) on the
instrument panel. See
Engine
Cooling System Messages on
page 5‑39 andEngine Power
Messages on page 5‑41.
If the decision is made not to lift the
hood when this warning appears,
but instead get service help right
away. See Roadside Assistance
Program on page 13‑5.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.

Black plate (26,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-26 Vehicle Care
Brakes
This vehicle has disc brakes. Disc
brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair. Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications in
Capacities and
Specifications on page 12‑2.
Brake linings should always be
replaced as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service might be
required.
Brake Adjustment
Every time the brakes are applied,
with or without the vehicle moving,
the brakes adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is
complex. Its many parts have to be
of top quality and work well together
if the vehicle is to have really good
braking. The vehicle was designed
and tested with top-quality brake
parts. When parts of the braking
system are replaced, be sure to get
new, approved replacement parts.
If this is not done, the brakes might
not work properly. For example,
installing disc brake pads that are
wrong for the vehicle, can change
the balance between the front and
rear brakes —for the worse. The
braking performance expected can
change in many other ways if the
wrong replacement brake parts are
installed.

Black plate (10,1)GMC Yukon/Yukon XL Owner Manual - 2012
11-10 Service and Maintenance
.As part of the multi‐point
inspection, trained dealer
technicians can visually inspect
the shocks and struts for signs
of leaking, blown seals,
or damage, and can advise
when service is needed.
Tires
Tires need to be properly inflated,
rotated, and balanced. Maintaining
the tires can save money, fuel, and
can reduce the risk of tire failure.
.Signs that the tires need to be
replaced include three or more
visible treadwear indicators; cord
or fabric showing through the
rubber; cracks or cuts in the
tread or sidewall; or a bulge or
split in the tire.
.Trained dealer technicians can
inspect and recommend the right
tires. Your dealer can also
provide tire/wheel balancing
services to ensure smooth
vehicle operation at all speeds.
Your dealer sells and services
name brand tires. Vehicle Care
To help keep the vehicle looking like
new, vehicle care products are
available from your dealer. For
information on how to clean and
protect the vehicle’s interior and
exterior, see
Interior Care on
page 10‑101 andExterior Care on
page 10‑98.
Wheel Alignment
Wheel alignment is critical for
ensuring that the tires deliver
optimal wear and performance.
.Signs that the alignment may
need to be adjusted include
pulling, improper vehicle
handling, or unusual tire wear.
.Your dealer has the required
equipment to ensure proper
wheel alignment. Windshield
For safety, appearance, and the
best viewing, keep the windshield
clean and clear.
.Signs of damage include
scratches, cracks, and chips.
.Trained dealer technicians can
inspect the windshield and
recommend proper replacement
if needed.
Wiper Blades
Wiper blades need to be cleaned
and kept in good condition to
provide a clear view.
.Signs of wear include streaking,
skipping across the windshield,
and worn or split rubber.
.Trained dealer technicians can
check the wiper blades and
replace them when needed.

Black plate (9,1)GMC Yukon/Yukon XL Owner Manual - 2012
INDEX i-9
OnStar®
Additional Information . . . . . . . . 14-5
Connections . . . . . . . . . . . . . . . . . . 14-4
Diagnostics . . . . . . . . . . . . . . . . . . . 14-5
Emergency . . . . . . . . . . . . . . . . . . . 14-2
Navigation . . . . . . . . . . . . . . . . . . . . 14-2
Overview . . . . . . . . . . . . . . . . . . . . . 14-1
Security . . . . . . . . . . . . . . . . . . . . . . 14-2
OnStar
®System . . . . . . . . . . . . . . . 1-27
Operation, Infotainment System . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Ordering Service Publications . . . . . . . . 13-12
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . . . 10-23
Overheating, Engine . . . . . . . . . . 10-21
Overview, OnStar
®. . . . . . . . . . . . 14-1
P
Park Shifting into . . . . . . . . . . . . . . . . . . . 9-27
Shifting out of . . . . . . . . . . . . . . . . . 9-28
Park Tilt Mirrors . . . . . . . . . . . . . . . . 2-19
Parking Assist, Ultrasonic . . . . . . . . . . . . . 9-53
Brake . . . . . . . . . . . . . . . . . . . . . . . . . 9-45
Brake and P (Park)
Mechanism Check . . . . . . . . 10-33
Over Things That Burn . . . . . . . 9-29
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . . 5-19
Passenger Sensing System . . . 3-38
Perchlorate Materials Requirements, California . . . . . 10-3
Personalization Vehicle . . . . . . . . . . . . . . . . . . . . . . . 5-47
Phone Bluetooth . . . . . . . . . . . . . . . . . . . . . 7-47 Power
Door Locks . . . . . . . . . . . . . . . . . . . . 2-8
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . 2-17
Outlets . . . . . . . . . . . . . . . . . . . . . . . . 5-9
Protection, Battery . . . . . . . . . . . . 6-10
Retained Accessory (RAP) . . . 9-27
Seat Adjustment . . . . . . . . . . . . . . . 3-4
Steering Fluid . . . . . . . . . . . . . . . 10-24
Windows . . . . . . . . . . . . . . . . . . . . . 2-21
Power Assist Steps . . . . . . . . . . . . 2-13
Pregnancy, Using Safety Belts . . . . . . . . . . . . . . . . . . . . . . . . . 3-27
Privacy Radio FrequencyIdentification (RFID) . . . . . . . 13-16
Program
Courtesy Transportation . . . . . . 13-8
Proposition 65 Warning, California . . . . . . . . . . . . . . . . . . . . . 10-3

Black plate (14,1)GMC Yukon/Yukon XL Owner Manual - 2012
i-14 INDEX
Vehicle (cont'd)Remote Start . . . . . . . . . . . . . . . . . . 2-5
Security . . . . . . . . . . . . . . . . . . . . . . 2-14
Towing . . . . . . . . . . . . . . . . . . . . . . 10-93
Vehicle Care Tire Pressure . . . . . . . . . . . . . . . 10-56
Vehicle Identification Service Parts IdentificationLabel . . . . . . . . . . . . . . . . . . . . . . . . 12-1
Ventilation, Air . . . . . . . . . . . . . . . . . 8-13
Visors . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Voltmeter Gauge . . . . . . . . . . . . . . 5-17W
Warning Brake System Light . . . . . . . . . . . 5-23
Warning Lights, Gauges, and Indicators . . . . . . . . . . . . . . . . 5-11
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . iv Cautions and Danger . . . . . . . . . . . .iv
Hazard Flashers . . . . . . . . . . . . . . . 6-5
Washer Fluid . . . . . . . . . . . . . . . . . 10-25
Washer Fluid Messages . . . . . . . 5-47
Wheels Alignment and TireBalance . . . . . . . . . . . . . . . . . . . 10-68
Different Size . . . . . . . . . . . . . . . 10-66
Replacement . . . . . . . . . . . . . . . 10-68 When It Is Time for New
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-63
Where to Put the Restraint . . . . 3-51
Windows . . . . . . . . . . . . . . . . . . . . . . 2-20 Power . . . . . . . . . . . . . . . . . . . . . . . . 2-21
Windshield Wiper/Washer . . . . . . . . . . . . . . . . . 5-5
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . 9-13
Wiper Blade Replacement . . . . 10-33
Wipers Rear Washer . . . . . . . . . . . . . . . . . . 5-5