
Black plate (23,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-23
.Idles for long periods in traffic.
.Tows a trailer. SeeTrailer
Towing on page 9‑79.
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 10‑7.
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.

Black plate (24,1)GMC Yukon/Yukon XL Owner Manual - 2011
10-24 Vehicle Care
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 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. The fans 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 10‑6 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.

Black plate (93,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-93
Towing
Towing the Vehicle
Notice:To avoid damage, the
disabled vehicle should be
towed with all four wheels off
the ground. Care must be taken
with vehicles that have low
ground clearance and/or special
equipment. Always flatbed on a
car carrier.
Consult your dealer or a
professional towing service if the
disabled vehicle must be towed.
See Roadside Assistance Program
on page 13‑6.
To tow the vehicle behind another
vehicle for recreational purposes,
such as behind a motor home, see
“Recreational Vehicle Towing” in this
section.
Recreational Vehicle
Towing
If the vehicle has a hybrid engine,
see the hybrid manual for more
information.
Recreational vehicle towing means
towing the vehicle behind another
vehicle –such as behind a motor
home. The two most common types
of recreational vehicle towing are
known as dinghy towing and dolly
towing. Dinghy towing is towing the
vehicle with all four wheels on the
ground. Dolly towing is towing the
vehicle with two wheels on the
ground and two wheels up on a
device known as a dolly. 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.

Black plate (94,1)GMC Yukon/Yukon XL Owner Manual - 2011
10-94 Vehicle Care
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.
Four-Wheel Drive Vehicles
with a Two Speed Automatic
Transfer Case
Use the following procedure to
dinghy tow a four-wheel drive
vehicle with a two speed automatic
transfer case:
1. Position the vehicle being towed
behind the tow vehicle and shift
the transmission to P (Park).
2. Turn the engine off and firmly set the parking brake.
3. Securely attach the vehicle being towed to the tow vehicle.

Black plate (95,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-95
{WARNING
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). The driver or others
could be injured. Make sure the
parking brake is firmly set before
the transfer case is shifted to
N (Neutral).
4. Shift the transfer case to N (Neutral). See “Shifting into
Neutral” under“Four-Wheel
Drive” for the proper procedure
to select the Neutral position for
the vehicle.
5. Release the parking brake only after the vehicle being towed is
firmly attached to the towing
vehicle.
6. Turn the ignition to LOCK/OFF and remove the key —the
steering wheel will still turn. After towing, see
“Shifting Out of
Neutral” under“Four-Wheel Drive”
for the proper procedure to take the
vehicle out of the Neutral position.
Dolly Towing –Front Towing
(Front Wheels Off the Ground)
Two-Wheel-Drive Vehicles and
Four-Wheel Drive Vehicles
with a Single Speed Automatic
Transfer Case
Notice: If a two-wheel drive
vehicle or a four-wheel drive
vehicle with a single speed automatic transfer case is towed
with the rear wheels on the
ground, the transmission could
be damaged. The repairs would
not be covered by the vehicle
warranty. Never tow the vehicle
with the rear 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 the
rear 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 (96,1)GMC Yukon/Yukon XL Owner Manual - 2011
10-96 Vehicle Care
To dolly tow a two‐wheel‐drive
vehicle or a four-wheel drive
vehicle with a single speed
automatic transfer case, the
vehicle must be towed with the
rear wheels on the dolly. See“Rear
Towing (Rear Wheels Off the
Ground)” later in this section for
more information. Four-Wheel Drive Vehicles
with a Two Speed Automatic
Transfer Case
Use the following procedure to dolly
tow a four-wheel drive vehicle from
the front:
1. Attach the dolly to the tow
vehicle following the dolly
manufacturer's instructions.
2. Drive the front wheels onto the dolly. 3. Shift the transmission to
P (Park).
4. Firmly set the parking brake.
{WARNING
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). The driver or others
could be injured. Make sure the
parking brake is firmly set before
the transfer case is shifted to
N (Neutral).
5. Use an adequate clamping device designed for towing to
ensure that the front wheels are
locked into the straight position.

Black plate (97,1)GMC Yukon/Yukon XL Owner Manual - 2011
Vehicle Care 10-97
6. Shift the transfer case toN (Neutral). See “Shifting into
N (Neutral)” under“Four-Wheel
Drive”.
7. Secure the vehicle to the dolly following the manufacturer's
instructions.
8. Release the parking brake only after the vehicle being towed is
firmly attached to the towing
vehicle.
9. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of
N (Neutral)” under“Four-Wheel
Drive”.Rear Towing (Rear Wheels Off
the Ground)
Two-Wheel-Drive Vehicles and
Four-Wheel Drive Vehicles with a
Single Speed Automatic
Transfer Case
Use the following procedure to dolly
tow the vehicle from the rear:
1. Attach the dolly to the tow vehicle following the dolly
manufacturer's instructions. 2. Drive the rear wheels onto the
dolly.
3. Firmly set the parking brake. See Parking Brake on
page 9‑51.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the manufacturer's
instructions.
6. Use an adequate clamping device designed for towing to
ensure that the front wheels are
locked into the straight position.
7. For four-wheel drive vehicles with a single speed automatic
transfer case, turn the transfer
case knob to the Two-Wheel
High position.
8. Turn the ignition to LOCK/OFF.

Black plate (98,1)GMC Yukon/Yukon XL Owner Manual - 2011
10-98 Vehicle Care
Four-Wheel Drive Vehicles with a
Two Speed Automatic
Transfer Case
Use the following procedure to dolly
tow a four-wheel drive vehicle from
the rear:
1. Attach the dolly to the towvehicle following the dolly
manufacturer's instructions.
2. Drive the rear wheels onto the dolly.
3. Firmly set the parking brake. See Parking Brake on
page 9‑51.
4. Put the transmission in P (Park).
5. Secure the vehicle to the dolly following the manufacturer's
instructions.
6. Use an adequate clamping device designed for towing to
ensure that the front wheels are
locked into the straight position.{WARNING
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). The driver or others
could be injured. Make sure the
parking brake is firmly set before
the transfer case is shifted to
N (Neutral).
7. Shift the transfer case to N (Neutral). See “Shifting into
N (Neutral)” under“Four-Wheel
Drive”.
8. Turn the ignition to LOCK/OFF.
After towing, see “Shifting Out of
N (Neutral)” under“Four-Wheel
Drive”.
Appearance Care
Exterior Care
Weatherstrips
Silicone grease on weatherstrips will
make them last longer, seal better,
and not stick or squeak. Apply
silicone grease with a clean cloth.
During very cold, damp weather
frequent application may be
required. See Recommended Fluids
and Lubricants on page 11‑7.
Washing the Vehicle
The best way to preserve the
vehicle's finish is to keep it clean by
washing it often.
Notice: Certain cleaners contain
chemicals that can damage the
emblems or nameplates on the
vehicle. Check the cleaning
product label. If it states that it
should not be used on plastic
parts, do not use it on the vehicle