check engine light GMC YUKON 2012 User Guide

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 (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.

Black plate (70,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-70 Driving and Operating
Making Turns
Notice:Making very sharp turns
while trailering could cause the
trailer to come in contact with the
vehicle. The vehicle could be
damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer, make
wider turns than normal. Do this
so the trailer will not strike soft
shoulders, curbs, road signs, trees
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
panel will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a lower
gear before starting down a long or
steep downgrade. If the transmission is not shifted down, the
brakes might get hot and no longer
work well.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
The tow/haul mode may be used if
the transmission shifts too often.
See
Tow/Haul Mode Light on
page 5‑25.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)
for a few minutes before turning the engine off. If the overheat warning
comes on, see
Engine Overheating
on page 10‑21.
Parking on Hills
{WARNING
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.

Black plate (86,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-86 Driving and Operating
Trailer Sway
Control (TSC)
Non-hybrid vehicles with StabiliTrak
have a Trailer Sway Control (TSC)
feature. If the vehicle is towing a
trailer and the system detects that
the trailer is swaying, the vehicle
brakes are applied without the driver
pressing the brake pedal. If the
vehicle is equipped with the
Integrated Trailer Brake Control
(ITBC) system, StabiliTrak may also
apply the trailer brakes. The TCS/
StabiliTrak warning light will flash on
the instrument panel cluster to notify
the driver to reduce speed. If the
trailer continues to sway, StabiliTrak
will reduce engine torque to help
slow the vehicle. SeeStabiliTrak
®
System on page 9‑46 for more
information.
Adding non‐dealer accessories can
affect the vehicle performance. See
Accessories and Modifications on
page 10‑3 for more information.
Conversions and
Add-Ons
Add-On Electrical
Equipment
Notice:Do not add anything
electrical to the vehicle unless
you check with your dealer first.
Some electrical equipment can
damage the vehicle and the
damage would not be covered by
the vehicle's warranty. Some
add-on electrical equipment can
keep other components from
working as they should.
Add-on equipment can drain the
vehicle's 12‐volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle on page 3‑42 andAdding
Equipment to the Airbag-Equipped
Vehicle on page 3‑42.
Adding a Snow Plow or
Similar Equipment
Before installing a snow plow on the
vehicle, here are some things you
need to know:
Notice: If the vehicle does not
have the snow plow prep
package, adding a plow can
damage the vehicle, and the
repairs would not be covered by
warranty. Unless the vehicle was
built to carry a snow plow, do not
add one to the vehicle. If the
vehicle has the snow plow prep
package, called RPO VYU, then
the payload the vehicle can carry
will be reduced when a snow
plow is installed. The vehicle can
be damaged if either the front or
rear axle ratings or the Gross
Vehicle Weight (GVW) are
exceeded.

Black plate (15,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-15
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer.
Engine Air Cleaner/Filter
SeeEngine Compartment Overview
on page 10‑6 for the location of the
engine air cleaner/filter.
Inspect the air cleaner/filter at the
scheduled maintenance intervals
and replace it at the first oil change
after each 80 000 km (50,000 mi)
interval. See Maintenance Schedule
on page 11‑3 for more information.
If driving on dusty/dirty conditions,
inspect the filter at each engine oil
change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter,
remove the engine air cleaner/filter
from the vehicle by following
Steps 1 through 6. When the engine
air cleaner/filter is removed, lightly
shake it to release loose dust and
dirt. If the engine air cleaner/filter
remains covered with dirt, a new
filter is required. Never use
compressed air to clean the filter.
Replacing the Engine Air
Cleaner/Filter
1. Locate the air cleaner/filter
assembly. See Engine
Compartment Overview on
page 10‑6.
2. Loosen the four screws on the cover of the housing and lift up
the cover.

Black plate (27,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-27
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid. See
Engine Compartment Overview on
page 10‑6for the location of the
reservoir.
There are only two reasons why the
brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system can also cause
a low fluid level. Have the brake
hydraulic system fixed, since a
leak means that sooner or later
the brakes will not work well. Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove brake fluid,
as necessary, only when work is
done on the brake hydraulic system.
{WARNING
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system. See
“Checking Brake
Fluid” in this section.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5‑23. Refer to the Maintenance Schedule
to determine when to check the
brake fluid. See
Maintenance
Schedule on page 11‑3.
Checking Brake Fluid
Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview on
page 10‑6.
The fluid level should be above
MIN. If it is not, have the brake
hydraulic system checked to see if
there is a leak.

Black plate (9,1)GMC Yukon/Yukon XL Owner Manual - 2012
Service and Maintenance 11-9
.To avoid break‐down or failure to
start the vehicle, maintain a
battery with full cranking power.
.Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion‐free.
Belts
.Belts may need replacing if they
squeak or show signs of
cracking or splitting.
.Trained dealer technicians can
inspect the belts and
recommend replacement when
necessary.
Brakes
Brakes stop the vehicle and are
crucial to safe driving.
.Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
.Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle’s systems
and components. See
Recommended Fluids and
Lubricants on page 11‑11 for GM
approved fluids.
.Engine oil and windshield
washer fluid levels should be
checked at every fuel fill.
.Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled.
Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks.
With a multi‐point inspection, your
dealer can inspect the hoses and
advise if replacement is needed. Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking.
.With a multi‐point inspection,
your dealer can check the lamps
and note any concerns.
Shocks and Struts
Shocks and struts help aid in control
for a smoother ride.
.Signs of wear may include
steering wheel vibration, bounce/
sway while braking, longer
stopping distance, or uneven
tire wear.

Black plate (1,1)GMC Yukon/Yukon XL Owner Manual - 2012
INDEX i-1
A
Accessories andModifications . . . . . . . . . . . . . . . . . 10-3
Accessory Power . . . . . . . . . . . . . . 9-27
Active Fuel Management
®. . . . . 9-29
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . . . 9-86
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . 9-86
Additional Information, OnStar
®. . . . . . . . . . . . . . . . . . . . . . 14-5
Adjustable Throttle and Brake Pedal . . . . . . . . . . . . . . . . . . 9-22
Adjustments Lumbar, Front Seats . . . . . . . . . . . 3-4
Air Cleaner/Filter, Engine . . . . . 10-15
Air Vents . . . . . . . . . . . . . . . . . . . . . . 8-13
Airbag
Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . 3-42 Airbag System
Check . . . . . . . . . . . . . . . . . . . . . . . . 3-44
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . 3-36
Passenger Sensing System . . . . . . . . . . . . . . . . . . . . . . 3-38
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . 3-35
What Will You See after an Airbag Inflates? . . . . . . . . . . . . . 3-36
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . 3-34
Where Are the Airbags? . . . . . . 3-32
Airbags Passenger Status Indicator . . . 5-19
Readiness Light . . . . . . . . . . . . . . 5-18
Servicing Airbag-EquippedVehicles . . . . . . . . . . . . . . . . . . . . . 3-42
System Check . . . . . . . . . . . . . . . . 3-30
Alarm System Anti-theft . . . . . . . . . . . . . . . . . . . . . . 2-14
AM-FM Radio . . . . . . . . . . . . . . . . . . . 7-7 Antenna
Rear Side Window . . . . . . . . . . . . 7-13
Satellite Radio . . . . . . . . . . . . . . . . 7-14
Anti-theft Alarm System . . . . . . . . . . . . . . . . 2-14
Alarm System Messages . . . . . 5-44
Antilock Brake
System (ABS) . . . . . . . . . . . . . . . . 9-44
Warning Light . . . . . . . . . . . . . . . . . 5-24
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . 10-98
Interior . . . . . . . . . . . . . . . . . . . . . 10-101
Armrest Storage . . . . . . . . . . . . . . . . 4-1
Assistance Program, Roadside . . . . . . . . . . . . . . . . . . . . . 13-5
Audio Players . . . . . . . . . . . . . . . . . 7-14
CD . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
CD/DVD . . . . . . . . . . . . . . . . . . . . . . 7-19
Audio System Radio Reception . . . . . . . . . . . . . . 7-12
Rear Seat (RSA) . . . . . . . . . . . . . 7-45
Theft-Deterrent Feature . . . . . . . . 7-2

Black plate (2,1)GMC Yukon/Yukon XL Owner Manual - 2012
i-2 INDEX
AutomaticDimming Mirrors . . . . . . . . . . . . . . 2-19
Door Locks . . . . . . . . . . . . . . . . . . . . 2-8
Headlamp System . . . . . . . . . . . . . 6-4
Level Control . . . . . . . . . . . . . . . . . 9-50
Automatic Transmission . . . . . . . 9-31 Fluid . . . . . . . . . . . . . . . . . . . . . . . . 10-12
Manual Mode . . . . . . . . . . . . . . . . . 9-35
Shift Lock Control
Function Check . . . . . . . . . . . 10-32
Auxiliary
Roof Mounted Lamp . . . . . . . . . . . 6-7
Auxiliary Devices . . . . . . . . . . . . . . 7-30
Axle, Front . . . . . . . . . . . . . . . . . . . . 10-30
Axle, Rear . . . . . . . . . . . . . . . . . . . . 10-31
B
Battery . . . . . . . . . . . . . . . . . . . . . . . 10-28 Jump Starting . . . . . . . . . . . . . . . 10-88
Load Management . . . . . . . . . . . . . 6-9
Power Protection . . . . . . . . . . . . . 6-10
Voltage and ChargingMessages . . . . . . . . . . . . . . . . . . . 5-38
Blade Replacement, Wiper . . . 10-33
Bluetooth . . . . . . . . . . . . . . . . . . . . . . 7-47 Brake
Pedal and Adjustable
Throttle . . . . . . . . . . . . . . . . . . . . . . 9-22
Brake System Warning Light . . . 5-23
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 10-26 Antilock . . . . . . . . . . . . . . . . . . . . . . . 9-44
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 9-45
Fluid . . . . . . . . . . . . . . . . . . . . . . . . 10-27
Parking . . . . . . . . . . . . . . . . . . . . . . . 9-45
System Messages . . . . . . . . . . . . 5-38
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 9-4
Break-In, New Vehicle . . . . . . . . . 9-21
Bulb Replacement . . . . . . . . . . . . 10-39
Fog Lamps . . . . . . . . . . . . . . . . . . . . 6-6
Halogen Bulbs . . . . . . . . . . . . . . 10-37
Headlamp Aiming . . . . . . . . . . . 10-35
Headlamps . . . . . . . . . . . . . . . . . 10-37
License Plate Lamps . . . . . . . 10-38
Taillamps, Turn Signal,Stoplamps, and
Back-up Lamps . . . . . . . . . . . 10-37
Buying New Tires . . . . . . . . . . . . . 10-64
C
Calibration . . . . . . . . . . . . . . . . . . . . . . 5-6
California Fuel Requirements . . . . . . . . . . . 9-62
Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . 10-3
Warning . . . . . . . . . . . . . . . . . . . . . . 10-3
Camera, Rear Vision . . . . . . . . . . 9-57
Canadian Vehicle Owners . . . . . . . . iii
Capacities and Specifications . . . . . . . . . . . . . . . . 12-2
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . . . 9-30
Liftgate . . . . . . . . . . . . . . . . . . 2-9, 2-10
Winter Driving . . . . . . . . . . . . . . . . 9-13
Cargo
Cover . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Cautions, Danger, and Warnings . . . . . . . . . . . . . . . . . . . . . . . . iv
CD Player . . . . . . . . . . . . . . . . . . . . . 7-14
CD/DVD Player . . . . . . . . . . . . . . . . 7-19
Center Console Storage . . . . . . . . 4-2
Center Seat . . . . . . . . . . . . . . . . . . . . 3-4

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual - 2012
INDEX i-3
Chains, Tire . . . . . . . . . . . . . . . . . . 10-70
Charging System Light . . . . . . . . 5-20
CheckEngine Light . . . . . . . . . . . . . . . . . . 5-21
IgnitionTransmission Lock . . . . . . . . 10-33
Child Restraints
Infants and YoungChildren . . . . . . . . . . . . . . . . . . . . . 3-47
Lower Anchors and Tethers for Children . . . . . . . . . 3-53
Older Children . . . . . . . . . . . . . . . . 3-45
Securing . . . . . . . . . . . . . . . . 3-60, 3-63
Systems . . . . . . . . . . . . . . . . . . . . . . 3-50
Circuit Breakers . . . . . . . . . . . . . . 10-40
Cleaning Exterior Care . . . . . . . . . . . . . . . 10-98
Interior Care . . . . . . . . . . . . . . . 10-101
Climate Control Systems . . . . . . . 8-1 Air Conditioning . . . . . . . . . . . . . . . 8-1
Dual Automatic . . . . . . . . . . . . . . . . 8-4
Heating . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Rear . . . . . . . . . . . . . . . . . . . . 8-10, 8-11 Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Cluster, Instrument . . . . . . . . . . . . 5-12
Collision Damage Repair . . . . . . 13-9
Compass . . . . . . . . . . . . . . . . . . . . . . . 5-6
Connections, OnStar
®. . . . . . . . . 14-4
Continuous Damping Control (CDC) . . . . . . . . . . . . . . . . 9-50
Control of a Vehicle . . . . . . . . . . . . . 9-3
Convex Mirrors . . . . . . . . . . . . . . . . 2-17
Coolant Engine . . . . . . . . . . . . . . . . . . . . . . 10-17
Engine Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 5-16
Cooling System . . . . . . . . . . . . . . . 10-16 Engine Messages . . . . . . . . . . . . 5-39
Courtesy Transportation
Program . . . . . . . . . . . . . . . . . . . . . . 13-8
Cover Cargo . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Cruise Control . . . . . . . . . . . . . . . . . 9-51 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Cupholders . . . . . . . . . . . . . . . . . . . . . 4-1 Customer Assistance . . . . . . . . . . 13-4
Offices . . . . . . . . . . . . . . . . . . . . . . . . 13-3
Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . 13-4
Customer Information Service PublicationsOrdering Information . . . . . . 13-12
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . 13-1
D
Damage Repair, Collision . . . . . . 13-9
Danger, Warnings, andCautions . . . . . . . . . . . . . . . . . . . . . . . . iv
Data Recorders, Event . . . . . . . 13-14
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 6-3
Defensive Driving . . . . . . . . . . . . . . . 9-3
Delayed Locking . . . . . . . . . . . . . . . . 2-8
Devices, Auxiliary . . . . . . . . . . . . . 7-30
Diagnostics, OnStar
®. . . . . . . . . . 14-5
Distracted Driving . . . . . . . . . . . . . . . 9-2
Dome Lamps . . . . . . . . . . . . . . . . . . . 6-8