trailer GMC YUKON 2008 User Guide

Cleaning the Mirror
Use a paper towel or similar material dampened with
glass cleaner. Do not spray glass cleaner directly on the
mirror as that may cause the liquid cleaner to enter
the mirror housing.
Outside Manual Mirrors
Adjust your outside mirrors so you can just see the side of
your vehicle and have a clear view of objects behind you.
The mirrors can be folded in to enter narrow areas.
The use of hood-mounted air deectors and add-on
convex mirror attachments may adversely affect mirror
performance.
Outside Trailer-Tow Mirrors
If your vehicle has trailer towing type mirrors, they can
be adjusted so you can have a clear view of the
objects behind you. Manually pull out the mirror head to
extend it for better visibility when towing a trailer.
These mirrors can be manually folded forward or
rearward. The lower portion of the mirror is convex.
A convex mirror’s surface is curved so you can see more
from the driver’s seat. The convex mirror can be
adjusted manually to the driver’s preferred position for
better vision.
2-54

When the System Does Not Seem to
Work Properly
The driver disables the system.
The parking brake pedal is depressed.
The ultrasonic sensors are not clean. Keep your
vehicle’s rear bumper free of mud, dirt, snow,
ice and slush. For cleaning instructions, see
Washing Your Vehicle on page 5-111.
A trailer was attached to your vehicle, or a bicycle
or an object was hanging out of your liftgate/liftglass
during your last drive cycle, the red light may
illuminate in the rear display. Once the attached
object is removed, URPA will return to normal
operation.
A tow bar is attached to your vehicle.
The vehicle’s bumper is damaged. Take the vehicle
to your dealer/retailer to repair the system.
Other conditions may affect system performance,
such as vibrations from a jackhammer or the
compression of air brakes on a very large truck.
If the system is still disabled, after driving forward at
least 15 mph (25 km/h), take your vehicle to your
dealer/retailer.
OnStar®System
OnStar uses several innovative technologies and live
advisors to provide you with a wide range of safety,
security, information, and convenience services. If your
airbags deploy, the system is designed to make an
automatic call to OnStar Emergency advisors who can
request emergency services be sent to your location.
If you lock your keys in the vehicle, call OnStar at
1-888-4-ONSTAR and they can send a signal to unlock
your doors. If you need roadside assistance, press
the OnStar button and they can contact Roadside
Service for you.
OnStar service is provided to you subject to the
OnStar Terms and Conditions. You may cancel your
OnStar service at any time by contacting OnStar.
2-60

Reading Lamps
If your vehicle has reading lamps they are located on
the overhead console.
To turn on the reading lamps, press the button located
next to each lamp. To turn them off, press the button
again.
Your vehicle may also have reading lamps in other
locations. To turn the lamps on or off, press the button
located next to the lamp.
The lamps are xed and cannot be adjusted.
Electric Power Management
The vehicle has Electric Power Management (EPM) that
estimates the battery’s temperature and state of
charge. It then adjusts the voltage for best performance
and extended life of the battery.
When the battery’s state of charge is low, the voltage is
raised slightly to quickly put the charge back in. When
the state of charge is high, the voltage is lowered slightly
to prevent overcharging. If the vehicle has a voltmeter
gage or a voltage display on the Driver Information
Center (DIC), you may see the voltage move up
or down. This is normal. If there is a problem, an alert
will be displayed.The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles. This is
because the generator (alternator) may not be
spinning fast enough at idle to produce all the power
that is needed for very high electrical loads.
A high electrical load occurs when several of the
following loads are on: headlamps, high beams, fog
lamps, rear window defogger, climate control fan at high
speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.
EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator’s output
and the vehicle’s electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands of
some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels
of corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC)
message might be displayed, such as Battery Saver
Active or Service Battery Charging System. If this
message is displayed, it is recommended that the driver
reduce the electrical loads as much as possible. See
DIC Warnings and Messages on page 3-64.
3-21

This light comes on, as a check to show it is working,
when the ignition is turned ON/RUN but the engine is not
running. If the light does not come on, have it repaired.
This light also comes on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system on
your vehicle. Diagnosis and service might be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
If the Light is Flashing
The following can prevent more serious damage to your
vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid steep uphill grades.
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.If the light stops ashing and remains on steady, see “If
the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park the vehicle.
Turn the ignition off, wait at least 10 seconds, and restart
the engine. If the light remains on steady, see “If the
Light Is On Steady” following. If the light is still ashing,
follow the previous steps and see your dealer/retailer
for service as soon as possible.
If the Light Is On Steady
You might be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling the Tank on page 5-9. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap allows fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed should
turn the light off.
3-49

Your Driving, the Road, and Your Vehicle..........4-2
Defensive Driving...........................................4-2
Drunk Driving.................................................4-2
Control of a Vehicle........................................4-3
Braking.........................................................4-4
Antilock Brake System (ABS)...........................4-5
Braking in Emergencies...................................4-6
Locking Rear Axle..........................................4-6
StabiliTrak
®System........................................4-6
Steering........................................................4-9
Off-Road Recovery.......................................4-11
Passing.......................................................4-11
Loss of Control.............................................4-12
Off-Road Driving...........................................4-13
Driving at Night............................................4-26
Driving in Rain and on Wet Roads..................4-26
Before Leaving on a Long Trip.......................4-28Highway Hypnosis........................................4-28
Hill and Mountain Roads................................4-29
Winter Driving..............................................4-30
If Your Vehicle is Stuck in Sand, Mud, Ice,
or Snow...................................................4-33
Rocking Your Vehicle to Get It Out.................4-34
Recovery Hooks...........................................4-34
Loading Your Vehicle....................................4-35
Adding a Snow Plow or Similar Equipment.......4-41
Towing..........................................................4-45
Towing Your Vehicle.....................................4-45
Recreational Vehicle Towing...........................4-45
Level Control...............................................4-48
Autoride
®.....................................................4-49
Towing a Trailer...........................................4-49
Trailer Recommendations...............................4-63
Section 4 Driving Your Vehicle
4-1

5.Determine the combined weight of luggage
and cargo being loaded on the vehicle. That
weight may not safely exceed the available
cargo and luggage load capacity calculated in
Step 4.
6.If your vehicle will be towing a trailer, the load
from your trailer will be transferred to your
vehicle. Consult this manual to determine how
this reduces the available cargo and luggage
load capacity of your vehicle. SeeTowing
a Trailer on page 4-49for important
information on towing a trailer, towing safety
rules and trailering tips.
Item Description Total
AVehicle Capacity
Weight for
Example 1=1,000 lbs
(453 kg)
BSubtract Occupant
Weight 150 lbs
(68 kg)×2=300 lbs (136 kg)
CAvailable Occupant
and Cargo Weight=700 lbs (317 kg)
Example 1
4-37

Here are some important things to consider before you
do recreational vehicle towing:
What’s the towing capacity of the towing vehicle?
Be sure you read the tow vehicle manufacturer’s
recommendations.
How far will you tow? Some vehicles have
restrictions on how far and how long they can tow.
Do you have the proper towing equipment?
See your dealer/retailer or trailering professional for
additional advice and equipment recommendations.
Is your vehicle ready to be towed? Just as you
would prepare your vehicle for a long trip, you’ll
want to make sure your vehicle is prepared to be
towed. SeeBefore Leaving on a Long Trip on
page 4-28.
Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If you tow a two-wheel-drive vehicle with all
four wheels on the ground, the transmission
could be damaged. The repairs would not be
covered by your warranty. Do not tow a
two-wheel-drive vehicle with all four wheels on the
ground.
Two-wheel-drive vehicles should not be towed with all
four wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed.
4-46

Autoride®
If equipped, the Autoride®feature will provide a superior
vehicle ride and handling under a variety of passenger
and loading conditions.
The system is fully automatic and uses 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
®also interacts with the tow/haul switch that,
when engaged, 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. SeeTow/Haul Mode Light on
page 3-53for more information.
Towing a Trailer
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
Do not tow a trailer during break-in. SeeNew Vehicle
Break-In on page 2-26for more information.
{CAUTION:
If you do not use the correct equipment and
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well — or even
at all. You and your passengers could be
seriously injured. You may also damage your
vehicle; the resulting repairs would not be
covered by your warranty. Pull a trailer only if
you have followed all the steps in this section.
Ask your dealer/retailer for advice and
information about towing a trailer with your
vehicle.
Notice:Pulling a trailer improperly can damage
your vehicle and result in costly repairs that would
not be covered by your warranty. Always follow
the instructions in this section and check with your
dealer/retailer for more information about towing
a trailer with your vehicle.
To identify the trailering capacity of your vehicle, you
should read the information in “Weight of the Trailer” that
appears later in this section.
4-49

Trailering is different than just driving your vehicle by
itself. Trailering means changes in acceleration, braking,
handling, durability and fuel economy. Successful,
safe trailering takes correct equipment, and it has to be
used properly.
That’s the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers. So please read this section carefully before
you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you’ll be driving. A good source for
this information can be state or provincial police.
Consider using a sway control. See “Hitches” later
in this section.
Don’t tow a trailer at all during the rst 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that you
tow a trailer, don’t drive over 50 mph (80 km/h)
and don’t make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or, if necessary, a
lower gear selection if the transmission shifts
too often (e.g., under heavy loads and/or hilly
conditions). See “Tow/Haul Mode” later in
this section.
Three important considerations have to do with weight:
The weight of the trailer
The weight of the trailer tongue
The weight on your vehicle’s tires
4-50

Tow/Haul Mode
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. The purpose of the
Tow/Haul mode is to:
Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.
Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
Improve control of vehicle speed while requiring
less throttle pedal activity when pulling a heavy
trailer or a large or heavy load.
Increase the charging system voltage to assist in
recharging a battery installed in a trailer.Press this button at the end of the shift lever to
enable/disable the tow/haul mode.
A light on the instrument
panel will illuminate to
indicate that tow/haul
mode has been selected.
4-51