service GMC YUKON XL 2014 Repair Manual

Black plate (69,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-69
The seven-wire harness contains
the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are
installed in the underhood electrical
center, but the wires are not
connected. They should be
connected by your dealer or a
qualified service center. Heavy-Duty Trailer Wiring Harness
Package
The vehicle is equipped with the
seven-wire trailer towing harness.
This harness with a seven-pin
universal trailer connector is
attached to a bracket on the hitch
platform.
The seven-wire harness contains
the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are
installed in the underhood electrical
center, but the wires are not
connected. They should be
connected by your dealer or a
qualified service center.
If charging a remote (non-vehicle)
battery, press the tow/haul mode
button located at the end of the shift
lever. This will boost the vehicle
system voltage and properly charge
the battery. If the trailer is too light
for tow/haul mode, turn on the
headlamps as a second way to
boost the vehicle system and
charge the battery.

Black plate (70,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
9-70 Driving and Operating
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part of
the trailer wiring package. These
provisions are for an electric brake
controller. The instrument panel
contains blunt cut wires near the
data link connector for the trailer
brake controller. The harness
contains the following wires:
.Dark Blue: Brake Signal to
Trailer Connector
.Red/Black: Battery
.Light Blue/White: Brake Switch
.White: Ground
It should be installed by your dealer
or a qualified service center.
If the vehicle is equipped with an
ITBC, the blunt cuts exist, but are
not connected further in the
harness. If an aftermarket trailer
brake controller is installed, the
ITBC must be disconnected. Do not power both ITBC and aftermarket
controllers to control the trailer
brakes at the same time.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
tow/haul mode.
This indicator light on the instrument
panel cluster comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See
Tow/Haul
Mode on page 9-32 for more
information.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 percent of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” earlier in
the section. Tow/Haul is most useful
under the following driving
conditions:
.When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
.When pulling a heavy trailer or a
large or heavy load in stop and
go traffic.
.When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.

Black plate (73,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Driving and Operating 9-73
Gain setting. After the Trailer
Brake Display Page is displayed,
each press and release of the
gain buttons will then cause the
Trailer Gain setting to change.
.Activating the Manual Trailer
Brake Apply lever
.Connecting a trailer equipped
with electric trailer brakes
All DIC warning and service
messages must first be
acknowledged by the driver by
pressing the odometer trip stem or
the DIC Vehicle Information button
(if equipped) before the Trailer
Brake Display Page can be
displayed and Trailer Gain can be
adjusted.
TRAILER GAIN –This setting is
displayed anytime the Trailer Brake
Display Page is active. This setting
can be adjusted from 0.0 to 10.0
with either a trailer connected or
disconnected. To adjust the Trailer
Gain, press one of the Trailer Gain
adjustment buttons located on the
Trailer Brake Control Panel. Press and hold a gain button to cause the
Trailer Gain to continuously adjust.
To turn the output to the trailer off,
adjust the Trailer Gain setting to
0.0 (zero).
0.0 (zero) gain is the factory default
setting. To properly adjust trailer
gain, see the Trailer Gain
Adjustment Procedure later in this
section.
TRAILER OUTPUT
–This is
displayed any time a trailer with
electric brakes is connected. Output
to the electric brakes is based on
the amount of vehicle braking
present and relative to the Trailer
Gain setting. Output is displayed
from 0 to 10 bars for each gain
setting.
Vehicles with Trailer Sway Control
(TSC) or Hill Start Assist (HSA),
output to the electric trailer brakes
may be displayed when the systems
are active. See Trailer Sway Control
(TSC) on page 9-76 andHill Start
Assist (HSA) on page 9-41. The Trailer Output will indicate
“- - - - - -“
on the Trailer Brake
Display Page whenever the
following occur:
.No trailer is connected.
.A trailer without electric brakes
is connected (no DIC message
is displayed).
.A trailer with electric brakes has
become disconnected (a
CHECK TRAILER WIRING
message will also be displayed
on the DIC).
.There is a fault present in the
wiring to the electric trailer
brakes (a CHECK TRAILER
WIRING message will also be
displayed on the DIC).
.There is a fault in the ITBC
system (a SERVICE TRAILER
BRAKE SYSTEM message will
also be displayed in the DIC).

Black plate (74,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
9-74 Driving and Operating
Manual Trailer Brake Apply
The Manual Trailer Brake Apply
Lever is located on the Trailer Brake
Control Panel and is used to apply
the trailer’s electric brakes
independent of the vehicle’s brakes.
This lever is used in the Trailer Gain
Adjustment Procedure to properly
adjust the power output to the trailer
brakes. Sliding the lever to the left
will apply only the trailer brakes.
The power output to the trailer is
indicated in the Trailer Brake
Display Page in the DIC. If the
vehicle’s service brakes are applied
while using the Manual Trailer Brake
Apply Lever, the trailer output power
will be the greater of the two.
The trailer and the vehicle's brake
lamps will come on when either
vehicle braking or manual trailer
brakes are applied. Trailer Gain Adjustment Procedure
Trailer Gain should be set for a
specific trailering condition and must
be adjusted any time vehicle
loading, trailer loading or road
surface conditions change.
Setting the Trailer Gain properly is
needed for the best trailer stopping
performance. A trailer that is
over-gained may result in locked
trailer brakes. A trailer that is
under-gained may result in not
enough trailer braking. Both of these
conditions may result in poorer
stopping and stability of the vehicle
and trailer.
Use the following procedure to
correctly adjust Trailer Gain for each
towing condition:
1. Make sure the trailer brakes are
in proper working condition.
2. Connect a properly loaded trailer to the vehicle and make all
necessary mechanical and electrical connections. See
Vehicle Load Limits on
page 9-15
for more information.
3. After the electrical connection is made to a trailer equipped with
electric brakes:
.A TRAILER CONNECTED
message will be briefly
displayed on the DIC
display.
.The Trailer Brake Display
Page will appear on the
DIC showing TRAILER
GAIN and TRAILER
OUTPUT.
.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.

Black plate (76,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
9-76 Driving and Operating
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.
Trailer Sway
Control (TSC)
Vehicles with StabiliTrak have a
TSC feature. Trailer sway is
unintended side-to-side motion of a
trailer while being towed. If the
vehicle is towing a trailer and the
TSC detects that sway is increasing,
the vehicle brakes are selectively
applied at each wheel, to help
reduce excessive trailer sway. If the
vehicle is equipped with the
Integrated Trailer Brake Control
(ITBC) system, and the trailer has
the electric actuated brake system,
StabiliTrak may also apply the trailer
brakes.

Black plate (1,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil Life System . . . . . . 10-9
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-10
Engine Air Cleaner/Filter . . . . 10-13
Cooling System . . . . . . . . . . . . 10-14
Engine Coolant . . . . . . . . . . . . . 10-15
Engine Overheating . . . . . . . . 10-18
Overheated Engine Protection
Operating Mode . . . . . . . . . . . 10-19 Engine Fan . . . . . . . . . . . . . . . . . 10-20
Power Steering Fluid . . . . . . . 10-20
Washer Fluid . . . . . . . . . . . . . . . 10-21
Brakes . . . . . . . . . . . . . . . . . . . . . 10-21
Brake Fluid . . . . . . . . . . . . . . . . . 10-22
Battery . . . . . . . . . . . . . . . . . . . . . 10-24
Four-Wheel Drive . . . . . . . . . . . 10-25
Front Axle . . . . . . . . . . . . . . . . . . 10-25
Rear Axle . . . . . . . . . . . . . . . . . . 10-26
Starter Switch Check . . . . . . . 10-27
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-27
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-27
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-28
Wiper Blade Replacement . . . . . . . . . . . . . . 10-28
Glass Replacement . . . . . . . . 10-29
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-29
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-30
Halogen Bulbs . . . . . . . . . . . . . . 10-30 Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-30
License Plate Lamp . . . . . . . . 10-31
Replacement Bulbs . . . . . . . . . 10-31
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-31
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-32
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-32
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-36
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-39
All-Season Tires . . . . . . . . . . . . 10-40
Winter Tires . . . . . . . . . . . . . . . . 10-41
Summer Tires . . . . . . . . . . . . . . 10-41
All-Terrain Tires . . . . . . . . . . . . 10-41
Tire Sidewall Labeling . . . . . . 10-41
Tire Designations . . . . . . . . . . . 10-44
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-45
Tire Pressure . . . . . . . . . . . . . . . 10-48
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-49

Black plate (2,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
10-2 Vehicle Care
Tire Pressure MonitorOperation . . . . . . . . . . . . . . . . . 10-50
Tire Inspection . . . . . . . . . . . . . . 10-53
Tire Rotation . . . . . . . . . . . . . . . 10-54
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . 10-55
Buying New Tires . . . . . . . . . . . 10-56
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . 10-57
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . 10-58
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . 10-59
Wheel Replacement . . . . . . . . 10-60
Tire Chains . . . . . . . . . . . . . . . . . 10-60
If a Tire Goes Flat . . . . . . . . . . 10-61
Tire Changing . . . . . . . . . . . . . . 10-63
Secondary Latch System . . . 10-72
Full-Size Spare Tire . . . . . . . . 10-75Jump Starting
Jump Starting . . . . . . . . . . . . . . 10-76
Towing
Towing the Vehicle . . . . . . . . . 10-80
Recreational Vehicle Towing . . . . . . . . . . . . . . . . . . . . 10-81
Appearance Care
Exterior Care . . . . . . . . . . . . . . . 10-86
Interior Care . . . . . . . . . . . . . . . . 10-89
Floor Mats . . . . . . . . . . . . . . . . . . 10-92
General Information
For service and parts needs, visit
your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks:
California Proposition
65 Warning
Most motor vehicles, including this
one, contain and/or emit chemicals
known to the State of California to

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Vehicle Care 10-3
cause cancer and birth defects or
other reproductive harm. Engine
exhaust, many parts and systems,
many fluids, and some component
wear by-products contain and/or
emit these chemicals.
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, safety belt pretensioners,
and lithium batteries contained in
Remote Keyless Entry transmitters,
may contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications
Adding non‐dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride andhandling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty.
Damage to vehicle components
resulting from modifications or the
installation or use of non‐GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle on
page 3-38.
Vehicle Checks
Doing Your Own
Service Work
{Warning
It can be dangerous to work on
your vehicle if you do not have
the proper knowledge, service
manual, tools, or parts. Always
follow owner manual procedures
and consult the service manual
for your vehicle before doing any
service work.
If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, see Service
Publications Ordering Information
on page 13-11.

Black plate (4,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
10-4 Vehicle Care
This vehicle has an airbag system.
Before attempting to do your own
service work, seeAirbag System
Check on page 3-39.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records on
page 11-15.
Notice: Even small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the
fluids, reservoir caps,
or dipsticks.Hood
To open the hood:
1. Pull the handle with this symbol on it. It is inside the vehicle to
the lower left of the steering
wheel.
2. Then go to the front of thevehicle and locate the secondary
hood release, near the center of
the grille.
3. Push the secondary hood release to the right.
4. Lift the hood. Before closing the hood, be sure
all the filler caps are on properly.
Then bring the hood from full
open to within 152 mm (6 in)
from the closed position, pause,
then push the front center of the
hood with a swift, firm motion to
fully close the hood.

Black plate (7,1)GMC Yukon/Yukon XL Owner Manual (GMNA-Localizing-U.S./Canada-
6081505) - 2014 - crc - 4/23/13
Vehicle Care 10-7
Checking Engine Oil
It is a good idea to check the engine
oil level at each fuel fill. In order to
get an accurate reading, the vehicle
must be on level ground. The
engine oil dipstick handle is a loop.
SeeEngine Compartment Overview
on page 10-5 for the location of the
engine oil dipstick.
Obtaining an accurate oil level
reading is essential:
1. If the engine has been running recently, turn off the engine and
allow several minutes for the oil
to drain back into the oil pan.
Checking the oil level too soon
after engine shutoff will not
provide an accurate oil level
reading.
{Warning
The engine oil dipstick handle
may be hot; it could burn you.
Use a towel or glove to touch the
dipstick handle. 2. Pull out the dipstick and clean it
with a paper towel or cloth, then
push it back in all the way.
Remove it again, keeping the tip
down, and check the level.
When to Add Engine Oil
If the oil is below the cross-hatched
area at the tip of the dipstick, add
1 L (1 qt) of the recommended oil
and then recheck the level. See
“Selecting the Right Engine Oil” in
this section for an explanation of
what kind of oil to use. For engine
oil crankcase capacity, see
Capacities and Specifications on
page 12-2.
Notice: Do not add too much oil.
Oil levels above or below the
acceptable operating range
shown on the dipstick are harmful to the engine. If you find that you
have an oil level above the
operating range, i.e., the engine
has so much oil that the oil level
gets above the cross-hatched
area that shows the proper
operating range, the engine could
be damaged. You should drain
out the excess oil or limit driving
of the vehicle and seek a service
professional to remove the
excess amount of oil.
See
Engine Compartment Overview
on page 10-5 for the location of the
engine oil fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through.
Selecting the Right Engine Oil
Selecting the right engine oil
depends on both the proper oil
specification and viscosity grade.
See Recommended Fluids and
Lubricants on page 11-12.