
Black plate (20,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
10-20 Vehicle Care
.Tows a trailer. SeeTrailer
Towing on page 9‑66.
If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral) while stopped.
If it is safe to do so, pull off the
road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally. If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is no sign of steam, idle the
engine for three minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
“Overheated
Engine Protection Operating Mode”
later in this section.
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message is displayed,
an overheat protection mode which
alternates firing groups of cylinders
helps prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe place
in an emergency. Driving extended distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Notice:
After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair. The
engine oil will be severely
degraded. Repair the cause of
coolant loss, change the oil and
reset the oil life system. See
Engine Oil on page 10‑6.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged. This
improves fuel economy and reduces
fan noise. Under heavy vehicle
loading, trailer towing, and/or high
outside temperatures, the fan speed
increases as the clutch more fully

Black plate (21,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
Vehicle Care 10-21
engages, so an increase in fan
noise may be heard. This is normal
and should not be mistaken as the
transmission slipping or making
extra shifts. It is merely the cooling
system functioning properly. The fan
will slow down when additional
cooling is not required and the
clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. Thefans will change to low speed when
additional cooling is no longer
required.
Power Steering Fluid
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
See
Engine Compartment Overview
on page 10‑5 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power Steering
Fluid
To check the power steering fluid:
1. Turn the key off and let the
engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.
The level should be at the FULL
COLD mark. If necessary, add only
enough fluid to bring the level up to
the mark.
What to Use
To determine what kind of fluid to
use, see Recommended Fluids and
Lubricants on page 11‑11. Always
use the proper fluid.

Black plate (36,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
10-36 Vehicle Care
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses Usage
1 Right Trailer Stop/ Turn Lamp
2 Electronic Stability Suspension Control,
Automatic Level
Control Exhaust
3 Left Trailer Stop/ Turn Lamp
4 Engine Controls
5 Engine Control Module, Throttle
Control
6 Trailer Brake Controller
7 Front Washer
8 Oxygen Sensors
9 Antilock Brakes System 2 Fuses Usage
10 Trailer Back-up Lamps
11 Driver Side Low-Beam Headlamp
12 Engine Control Module (Battery)
13 Fuel Injectors, Ignition Coils (Right Side)
14 Transmission Control Module (Battery)
15 Vehicle Back-up Lamps
16 Passenger Side Low-Beam Headlamp
17 Air Conditioning Compressor
18 Oxygen Sensors
19 Transmission Controls (Ignition)
20 Fuel Pump Fuses
Usage
21 Fuel System Control Module
22 Headlamp Washer
23 Rear Windshield Washer
24 Fuel Injectors, Ignition Coils (Left Side)
25 Trailer Parking Lamps
26 Driver Side Parking Lamps
27 Passenger Side Parking Lamps
28 Fog Lamps
29 Horn
30 Passenger Side High-Beam Headlamp
31 Daytime Running Lamps (DRL) (If
Equipped)
32 Driver Side High-Beam Headlamp

Black plate (37,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
Vehicle Care 10-37
FusesUsage
33 Daytime Running Lamps 2 (If Equipped)
34 Sunroof
35 Key Ignition System, Theft Deterrent
System
36 Windshield Wiper
37 SEO B2 Upfitter Usage (Battery)
38 Electric Adjustable Pedals
39 Climate Controls (Battery)
40 Airbag System (Ignition)
41 Amplifier
42 Audio System
43 Miscellaneous (Ignition), Cruise
Control
44 Liftgate Release Fuses
Usage
45 Airbag System (Battery)
46 Instrument Panel Cluster
47 Not Used
48 Auxiliary Climate Control (Ignition)
49 Center High-Mounted Stoplamp (CHMSL)
50 Rear Defogger
51 Heated Mirrors
52 SEO B1 Upfitter Usage (Battery)
53 Accessory Power Outlet, Cigarette
Lighter (If Equipped)
54 Automatic Level Control Compressor
Relay
55 Climate Controls (Ignition) Fuses
Usage
56 Engine Control Module, Secondary
Fuel Pump (Ignition)
J-Case Fuses Usage
57 Cooling Fan 1
58 Automatic Level Control Compressor
59 Heavy Duty Antilock Braking System
60 Cooling Fan 2
61 Antilock Brake System 1
62 Starter
63 Stud 2 (Trailer Brakes)
64 Left Bussed Electrical Center 1
65 Electric Running Boards

Black plate (38,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
10-38 Vehicle Care
J-CaseFuses Usage
66 Not Used
67 Transfer Case
68 Stud 1 (Trailer Connector Battery
Power)
69 Mid-Bussed Electrical Center 1
70 Climate Control Blower
71 Power Liftgate Module
72 Left Bussed Electrical Center 2
Relays Usage
FAN HI Cooling Fan High Speed
FAN LO Cooling Fan Low Speed
FAN
CNTRL Cooling Fan Control Relays
Usage
HDLP
LO/HID Low-Beam Headlamp
FOG
LAMP Front Fog Lamps
A/C
CMPRSR Air Conditioning
Compressor
STRTR Starter
PWR/TRN Powertrain
FUEL
PMP Fuel Pump
PRK
LAMP Parking Lamps
REAR
DEFOG Rear Defogger
RUN/
CRNK Switched PowerInstrument Panel Fuse
Block
The instrument panel fuse block
access door is located on the driver
side edge of the instrument panel.
Pull off the cover to access the fuse
block.

Black plate (85,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
Vehicle Care 10-85
Here are some important things to
consider before recreational vehicle
towing:
.What is the towing capacity of
the towing vehicle? Be sure to
read the tow vehicle
manufacturer's
recommendations.
.What is the distance that will be
travelled? Some vehicles have
restrictions on how far and how
long they can tow.
.Is the proper towing equipment
going to be used? See your
dealer or trailering professional
for additional advice and
equipment recommendations.
.Is the vehicle ready to be
towed? Just as preparing the
vehicle for a long trip, make sure
the vehicle is prepared to be
towed.
Dinghy Towing
Two-Wheel-Drive Vehicles and
Four-Wheel Drive Vehicles with a
Single Speed Automatic
Transfer Case
Notice:If the vehicle is towed
with all four wheels on the
ground, the drivetrain
components could be damaged.
The repairs would not be covered
by the vehicle warranty. Do not
tow the vehicle with all four
wheels on the ground. Two-wheel-drive vehicles and
four-wheel drive vehicles with a
single speed automatic transfer
case should not be towed with all
four wheels on the ground.
Two-wheel-drive transmissions have
no provisions for internal lubrication
while being towed. Four-wheel drive
vehicles with a single speed
automatic transfer case have no
neutral position and will spin the
transmission when the rear
wheels turn.

Black plate (2,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
11-2 Service and Maintenance
Because of the way people use
vehicles, maintenance needs vary.
There may need to be more
frequent checks and services. The
Additional Required Services‐
Normal are for vehicles that:
.Carry passengers and cargo
within recommended limits on
the Tire and Loading Information
label. See Vehicle Load Limits
on page 9‑16.
.Are driven on reasonable road
surfaces within legal driving
limits.
.Use the recommended fuel. See
Recommended Fuel on
page 9‑58.
Refer to the information in the
Maintenance Schedule Additional
Required Services ‐Normal chart.
The Additional Required Services ‐
Severe are for vehicles that are:
.Mainly driven in heavy city traffic
in hot weather.
.Mainly driven in hilly or
mountainous terrain.
.Frequently towing a trailer.
.Used for high speed or
competitive driving.
.Used for taxi, police, or delivery
service.
Refer to the information in the
Maintenance Schedule Additional
Required Services ‐Severe chart.
{WARNING
Performing maintenance work can
be dangerous and can cause
serious injury. Perform
maintenance work only if the
required information, proper tools,
and equipment are available.
If they are not, see your dealer to
have a trained technician do the
work. See Doing Your Own
Service Work on page 10‑3.
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.Check the engine oil level. See
Engine Oil on page 10‑6.
Once a Month
.Check the tire inflation
pressures. See Tire Pressure on
page 10‑50.
.Inspect the tires for wear. See
Tire Inspection on page 10‑55.
.Check the windshield washer
fluid level. See Washer Fluid on
page 10‑22.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system might not
indicate the need for vehicle service

Black plate (10,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
13-10 Customer Information
reported that the vehicle has
been repaired, Roadside
Assistance will provide bus or
commercial airline one-way
service (subject to availability)
for the person designated by you
to collect your vehicle at the
dealership's location if you or the
designated person are not in the
same town or city as the
dealership.
*These services are not provided for
U.S. or Canada residents. All
services provided in the U.S. and
Canada are at the owner's expense
and will be reimbursed by Roadside
Assistance.
Services Not Included in Roadside
Assistance
Roadside Assistance does not
cover or reimburse services for the
following:
.Events caused by fraud or bad
faith by the driver.
.Vehicle immobilization situations
due to a major force or
unforeseen circumstances, such
as natural phenomena of an
extraordinary nature,
earthquakes, volcanic eruptions,
and other cyclonic storms.
.Vehicle immobilization situations
arising from car accidents
caused by the driver of the
vehicle or third parties. This
means any occurrence that
causes physical injury to the
occupants and/or the vehicle
caused by external forces.
.Acts of terrorism, riot or uproar,
armed forces or police actions
which prevent timely delivery of
assistance services.
.Food service, beverages,
telephone calls, or other extra
costs. Accommodation costs
apply only to Mexico per the
terms and conditions of the
Roadside Assistance program.
.Any damage to the vehicle
without intent, derived from the
services provided.
.Cost of towing a trailer when
choosing a GMC dealer that is
nearest to the temporary storage
facility for the disabled vehicle.
.Cost of all maneuvers required
to access the vehicle when it is
not available to be towed.
.Cost of fuel provided.
Routine vehicle repair costs are not
covered by the Roadside
Assistance program. For more
information, see your new vehicle
warranty.
Contacting Roadside Assistance
Roadside Assistance services are of
no cost to you and available
24 hours a day, 365 days a year.
Costs are only incurred in situations
that exceed the limits of the
program, some of which are listed
previously in this section.