2012 GMC YUKON ignition

Black plate (42,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-42 Driving and Operating
Four-Wheel Drive
(Single Speed Automatic
Transfer Case)
If the vehicle has four-wheel drive,
you can send the engine's driving
power to all four wheels for extra
traction. Read the following before
using four-wheel drive.
Notice:Driving on clean, dry
pavement in Four-Wheel Drive
High for an extended period of
time may cause premature wear
on the vehicle's powertrain. Do
not drive on clean, dry pavement
in Four-Wheel Drive High for
extended periods of time.
While driving on clean dry pavement
and during tight turns, you may
experience a vibration in the
steering system.
Front Axle
The front axle engages and
disengages automatically when you
shift the transfer case. Some delay
for the axle to engage or disengage
is normal.
Automatic Transfer Case
The transfer case knob is located to
the left of the instrument panel
cluster.
Use this dial to shift into and out of
four-wheel drive. The vehicle has Four-Wheel Drive
with StabiliTrak
®. For information on
StabiliTrak, see StabiliTrak®System
on page 9‑46.
You can choose among three
driving settings:
Indicator lights in the switch show
you which setting you are in. The
indicator lights will come on briefly
when you turn on the ignition and
the last chosen setting will stay on.
If the lights do not come on, you
should take the vehicle to your
dealer for service. An indicator light
will flash while shifting. It will stay on
when the shift is completed. If for
some reason the transfer case
cannot make a requested shift, it will
return to the last chosen setting.
2
m(Two-Wheel Drive High): This
setting is used for driving in most
street and highway situations. The
front axle is not engaged in
two-wheel drive. This setting also
provides the best fuel economy.

Black plate (45,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-45
Braking in Emergencies
ABS allows the driver to steer and
brake at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Parking Brake
Set the parking brake by holding the
regular brake pedal down, then
pushing down the parking brake
pedal.If the ignition is on, the brake
system warning light will come on.
See
Brake System Warning Light on
page 5‑23.
Notice: Driving with the parking
brake on can overheat the brake
system and cause premature
wear or damage to brake system
parts. Make sure that the parking
brake is fully released and the
brake warning light is off before
driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the parking brake pedal.
If the parking brake is not released
when you begin to drive, the brake
system warning light will flash and a
chime will sound warning you that
the parking brake is still on.
If you are towing a trailer and are
parking on a hill, see Driving
Characteristics and Towing Tips on
page 9‑68.
Brake Assist
This vehicle has a brake assist
feature designed to assist the driver
in stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement the
power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle. The
stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time is
normal and the driver should
continue to apply the brake pedal as
the driving situation dictates. The
brake assist feature will
automatically disengage when the
brake pedal is released or brake
pedal pressure is quickly
decreased.

Black plate (50,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-50 Driving and Operating
Continuous Damping
Control (CDC)
This vehicle may have a continuous
damping control system called
Autoride
®or MagneRide™. With
this feature, improved vehicle ride
and handling is provided under a
variety of passenger and loading
conditions.
Autoride and MagneRide are fully
automatic and use a computer
controller to continuously monitor
vehicle speed, wheel to body
position, lift/dive and steering
position of the vehicle. The
controller then sends signals to
each shock absorber to
independently adjust the damping
level to provide the optimum
vehicle ride. Autoride and MagneRide also
interact with the tow/haul mode that,
when activated, will provide
additional control of the shock
absorbers. This additional control
results in better ride and handling
characteristics when the vehicle is
loaded or towing a trailer. See
“Tow/
Haul Mode” underTrailer Towing on
page 9‑72 for more information.
Automatic Level Control
The automatic level control rear
suspension is available on light‐duty
vehicles and comes as a part of the
Continuous Damping Control (CDC)
suspension, if equipped.
This type of level control is fully
automatic and will provide a better
leveled riding position as well as
better handling under a variety of
passenger and loading conditions. An air compressor connected to the
rear shocks will raise or lower the
rear of the vehicle to maintain
proper vehicle height. The system is
activated when the ignition key is
turned to ON/RUN and will
automatically adjust vehicle height
thereafter. The system may exhaust
(lower vehicle height) for up to
ten minutes after the ignition key
has been turned off. You may hear
the air compressor operating when
the height is being adjusted.
If a weight‐distributing hitch is being
used, it is recommended to allow
the shocks to inflate, thereby
leveling the vehicle prior to adjusting
the hitch.

Black plate (53,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-53
Ending Cruise Control
There are three ways to end cruise
control:
.To disengage cruise control,
step lightly on the brake pedal.
.Press the[on the steering
wheel.
.To turn off the cruise control,
press
Ion the steering wheel.
Erasing Speed Memory
The cruise control set speed is
erased from memory by pressing
the
Ibutton or if the ignition is
turned off.
Object Detection
Systems
Ultrasonic Parking Assist
If available, the Ultrasonic Rear
Parking Assist (URPA) system uses
sensors on the rear bumper to
assist with parking and avoiding
objects while in R (Reverse).
{WARNING
The URPA system does not
detect pedestrians, bicyclists,
animals, or any other objects
located below the bumper or that
are too close or too far from the
vehicle. To prevent injury, death,
or vehicle damage, even with
URPA, always check behind the
vehicle and check all mirrors
before backing.
How the System Works
URPA comes on automatically
when the shift lever is moved into
R (Reverse). A single tone sounds
to indicate the system is working.
URPA operates only at speeds less
than 8 km/h (5 mph).
An obstacle is indicated by
audible beeps. The time between
the beeps gets shorter as the
vehicle approaches the obstacle.
A continuous tone is heard when
the distance is less than
30 cm (12 in).
To be detected, objects must be at
least 25 cm (10 in) off the ground
and below liftgate level. Objects
must also be within 2.5 m (8 ft) from
the rear bumper. This distance may
be less during warmer or humid
weather.

Black plate (80,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-80 Driving and Operating
This symbol is located on the Trailer
Brake Control Panel on vehicles
with an Integrated Trailer Brake
Control System. The power output
to the trailer brakes is based on the
amount of brake pressure being
applied by the vehicle’s brake
system. This available power output
to the trailer brakes can be adjusted
to a wide range of trailering
situations.
The ITBC system is integrated with
the vehicle’s brake, anti‐lock brake
and StabiliTrak systems. In trailering
conditions that cause the vehicle’s
anti‐lock brake or StabiliTrak
systems to activate, power sent to
the trailer's brakes will be
automatically adjusted to minimize
trailer wheel lock-up. This does not
imply that the trailer has the
StabiliTrak system. If the vehicle’s brake, anti‐lock
brake or StabiliTrak systems are not
functioning properly, the ITBC
system may not be fully functional
or may not function at all. Make sure
all of these systems are fully
operational to ensure full
functionality of the ITBC system.
The ITBC system is powered
through the vehicle's electrical
system. Turning the ignition off will
also turn off the ITBC system. The
ITBC system is fully functional only
when the ignition is in ON or
in RUN.
The ITBC system can only be used
with trailers with electric brakes.{WARNING
Connecting a trailer that is not
compatible with the ITBC system
may result in reduced or complete
loss of trailer braking. There may
be an increase in stopping
distance or trailer instability which
could result in personal injury or
damage to the vehicle, trailer,
or other property. An aftermarket
controller may be available for
use with trailers with surge, air,
or electric‐over‐hydraulic trailer
brake systems. To determine the
type of brakes on the trailer and
the availability of controllers,
check with your trailer
manufacturer or dealer.

Black plate (84,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-84 Driving and Operating
.In the Trailer Output display
on the DIC,“- - - - - -“will
disappear if there is no
error present. Connecting a
trailer without electric
brakes will not clear the six
dashed lines.
4. Adjust the Trailer Gain by using the gain adjustment (+ / -)
buttons on the Trailer Brake
Control Panel.
5. Drive the vehicle with the trailer attached on a level road surface
representative of the towing
condition and free of traffic at
about 32 to 40 km/h (20 to
25 mph) and fully apply the
Manual Trailer Brake Apply
lever.
Adjusting trailer gain at speeds
lower than 32 to 40 km/h (20 to
25 mph) may result in an
incorrect gain setting. 6. Adjust the Trailer Gain to just
below the point of trailer wheel
lock-up, indicated by trailer
wheel squeal or tire smoke when
a trailer wheel locks.
Trailer wheel lock-up may not
occur if towing a heavily loaded
trailer. In this case, adjust the
Trailer Gain to the highest
allowable setting for the towing
condition.
7. Re-adjust Trailer Gain any time vehicle loading, trailer loading or
road surface conditions change
or if trailer wheel lock-up is
noticed at any time while towing
Other ITBC Related DIC Messages
In addition to displaying TRAILER
GAIN and TRAILER OUTPUT
through the DIC, trailer connection
and ITBC system status is displayed
in the DIC.
TRAILER CONNECTED –This
message will be briefly displayed
when a trailer with electric brakes is
first connected to the vehicle. This message will automatically turn off
in about ten seconds. The driver
can also acknowledge this message
before it automatically turns off.
CHECK TRAILER WIRING
–This
message will be displayed if:
1. The ITBC system first
determines connection to a
trailer with electric brakes and
then the trailer harness becomes
disconnected from the vehicle.
If the disconnect occurs while
the vehicle is stationary, this
message will automatically turn
off in about thirty seconds. This
message will also turn off if the
driver acknowledges this
message off or if the trailer
harness is re-connected.
If the disconnect occurs while
the vehicle is moving, this
message will continue until the
ignition is turned off. This
message will also turn off if the
driver acknowledges this
message off or if the trailer
harness is re-connected.

Black plate (85,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-85
2. There is an electrical fault in thewiring to the electric trailer
brakes. This message will
continue as long as there is an
electrical fault in the trailer
wiring. This message will also
turn off if the driver
acknowledges this message off.
To determine if the electrical fault is
on the vehicle side or trailer side of
the trailer wiring harness
connection, do the following:
1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the ignition OFF.
3. Wait ten seconds, then turn the ignition back to RUN. 4. If the CHECK TRAILER WIRING
message re-appears, the
electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING
message only re-appears when
connecting the trailer wiring
harness to the vehicle, the
electrical fault is on the
trailer side.
SERVICE TRAILER BRAKE
SYSTEM –This message will be
displayed when there is a problem
with the ITBC system. If this
message persists over multiple
ignition cycles there is problem with
the ITBC system. Take the vehicle
to an authorized GM dealer to have
the ITBC system diagnosed and
repaired. If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message is
displayed while driving the vehicle,
power is no longer available to the
trailer brakes. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.
An authorized GM dealer may be
able to diagnose and repair
problems with the trailer. However,
any diagnosis and repair of the
trailer is not covered under the
vehicle warranty. Please contact
your trailer dealer for assistance
with trailer repairs and trailer
warranty information.

Black plate (1,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-8
Engine Oil Life System . . . . . 10-10
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-12
Engine Air Cleaner/Filter . . . . 10-15
Cooling System . . . . . . . . . . . . 10-16
Engine Coolant . . . . . . . . . . . . . 10-17 Engine Overheating . . . . . . . . 10-21
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-23
Engine Fan . . . . . . . . . . . . . . . . . 10-23
Power Steering Fluid . . . . . . . 10-24
Washer Fluid . . . . . . . . . . . . . . . 10-25
Brakes . . . . . . . . . . . . . . . . . . . . . 10-26
Brake Fluid . . . . . . . . . . . . . . . . . 10-27
Battery . . . . . . . . . . . . . . . . . . . . . 10-28
Four-Wheel Drive . . . . . . . . . . . 10-29
Front Axle . . . . . . . . . . . . . . . . . . 10-30
Rear Axle . . . . . . . . . . . . . . . . . . 10-31
Starter Switch Check . . . . . . . 10-32
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-32
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-33
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-33
Wiper Blade Replacement . . . . . . . . . . . . . . 10-33
Glass Replacement . . . . . . . . 10-34
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-35
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-37
Halogen Bulbs . . . . . . . . . . . . . . 10-37
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-37
License Plate Lamp . . . . . . . . 10-38
Replacement Bulbs . . . . . . . . . 10-39
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-39
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-40
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-41
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-45
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-48
Tire Sidewall Labeling . . . . . . 10-50
Tire Designations . . . . . . . . . . . 10-52
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . 10-53
Tire Pressure . . . . . . . . . . . . . . . 10-56
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-58