2007 GMC YUKON grade

DRIVE (D):This position is for normal driving. It
provides the best fuel economy for your vehicle.
If you need more power for passing, and you are:
Going less than about 35 mph (55 km/h), push
your accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push
the accelerator all the way down.
Drive (D) can be used when towing a trailer,
carrying a heavy load, driving on steep hills,
or for off-road driving. You may want to shift the
transmission to a lower gear selection if the
transmission shifts too often.
Downshifting the transmission in slippery road
conditions could result in skidding, see Skidding
underLoss of Control on page 357.
When temperatures are very cold, the
Hydra-Matic
®Automatic Transmission’s gear
shifting may be delayed providing more stable
shifts until the engine warms up. Shifts may
be more noticeable with a cold transmission.
This difference in shifting is normal.MANUAL MODE (M):This position lets drivers
select the range of gears appropriate for current
driving conditions. If your vehicle has this feature,
see “Driver Shift Control” later in this section.
Notice:Spinning the tires or holding the
vehicle in one place on a hill using only
the accelerator pedal may damage the
transmission. If you are stuck, do not spin
the tires. When stopping on a hill, use
the brakes to hold the vehicle in place.
Your vehicle has a shift stabilization feature that
adjusts the transmission shifting to the current
driving conditions in order to reduce rapid upshifts
and downshifts. This shift stabilization feature is
designed to determine, before making an upshift,
if the engine will be able to maintain vehicle
speed by analyzing things such as throttle position,
vehicle load, and hill grade. If the shift stabilization
feature determines that a current vehicle speed
cannot be maintained, the transmission does
not upshift and instead holds the current gear.
In some cases, this may appear to be a delayed
shift, however the transmission is operating
normally.
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When in the MANUAL MODE (M) a number will
display next to the M, indicating the current gear
that has been selected. The number displayed in
the gear indicator is the highest gear that can be
used. However, your vehicle can automatically shift
to lower gears as it adjusts to driving conditions.
This means that all gears below that number are
available. When FIFTH (5) is selected, FIRST (1)
through FIFTH (5) gears are automatically shifted
by the vehicle, but SIXTH (6) cannot be used until
the plus/minus button located on the steering
column lever is used to change to the gear.
The DSC controls the vehicle and engine speed
while driving down a hill or towing a trailer, by
allowing you to select a desired range of gears.
The transmission will prevent a gear range until a
speed that is appropriate for current driving
conditions is achieved. If shifting is prevented for
any reason, the currently selected gear will
ash multiple times in the instrument panel cluster.
Grade Braking is not available when the Driver
Shift Control is active. SeeTow/Haul Mode
on page 150for more information.
While using the DSC, Cruise Control and the
Tow/Haul mode can be used.Tow/Haul Mode
Your vehicle has a tow/haul mode. The tow/haul
mode adjusts the transmission shift pattern to
reduce shift cycling, providing increased
performance, vehicle control, and transmission
cooling when towing or hauling heavy loads.
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Press the button located on the end of the shift
lever to turn the tow/haul on or off. When the
tow/haul is on, a light on the instrument panel
cluster will come on.
SeeTow/Haul Mode Light on page 242for more
information.
Also see “Tow Haul Mode” underTowing a Trailer
on page 400for more information.
The tow/haul mode works with the Autoride
®
feature, if the vehicle has this, to enhance the ride
when trailering or with a loaded vehicle. See
Autoride
®on page 399.
Grade Braking
Grade Braking assists when driving on a downhill
grade. It maintains the vehicle’s speed by
automatically implementing a shift schedule that
uses the engine and the transmission to slow
the vehicle. This reduces wear on the brakes
system and increases control of the vehicle. The
system constantly monitors the vehicle’s speed,
acceleration, throttle position, and whether
the brake pedal is being pressed, and determines
when to keep the current vehicle speed or to
slow down. The system will then automatically
command downshifts that reduces the vehicles
speed, until the brake pedal is no longer
being pressed. This indicates the desired vehicle
speed has been reached.
The tow/haul mode and grade braking shift
modes can be activated by pressing the button on
the end of the shift control stalk. While in the
DSC mode, grade braking is deactivated, allowing
the driver to select a gear.
SeeAutomatic Transmission Operation on
page 145for more information.
151

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 where we 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.A complete OnStar
®Owner’s Guide and the
Terms and Conditions of the OnStar®Subscription
Service Agreement are included in the vehicle’s
OnStar
®Subscriber Information packet located
in your vehicle. For more information, visit
www.onstar.com or www.onstar.ca, contact
OnStar
®at 1-888-4-ONSTAR (1-888-466-7827), or
press the OnStar®button to speak with an
OnStar®advisor 24 hours a day, 7 days a week.
OnStar®Services
For new vehicles equipped with OnStar®, the Safe
& Sound Plan is included for one year from the
date of purchase. You can extend this plan beyond
the rst year, or upgrade to the Directions &
Connections Plan to meet your needs. For more
information, press the OnStar
®button to speak
with an advisor.
164

This light will also come on during a malfunction in
one of two ways:
Light Flashing— A misre condition has
been detected. A misre increases vehicle
emissions and may damage the emission
control system on your vehicle. Diagnosis and
service may be required.
Light On Steady— An emission control
system malfunction has been detected on your
vehicle. Diagnosis and service may be
required.
If the Light is Flashing
The following may prevent more serious damage
to your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount
of cargo being hauled as soon as it is
possibleIf 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
your vehicle. Turn the key 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 for service as
soon as possible.
If the Light Is On Steady
You may 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 426.
The diagnostic system can determine if the fuel cap
has been left off or improperly installed. A loose or
missing fuel cap will allow fuel to evaporate into the
atmosphere. A few driving trips with the cap
properly installed should turn the light off.
238

{CAUTION:
Coasting downhill in NEUTRAL (N) or with
the ignition off is dangerous. Your brakes
will have to do all the work of slowing
down. They could get so hot that they
would not work well. You would then have
poor braking or even none going down a
hill. You could crash. Always have your
engine running and your vehicle in gear
when you go downhill.
Know how to go down hills. The most
important thing to know is this: let your engine
do some of the slowing down. Shift to a
lower gear when you go down a steep or
long hill.
Know how to go uphill. You may want to shift
down to a lower gear. The lower gears help
cool your engine and transmission, and
you can climb the hill better.
Stay in your own lane when driving on
two-lane roads in hills or mountains. Do not
swing wide or cut across the center of
the road. Drive at speeds that let you stay in
your own lane.
As you go over the top of a hill, be alert.
There could be something in your lane, like a
stalled car or an accident.
You may see highway signs on mountains
that warn of special problems. Examples
are long grades, passing or no-passing zones,
a falling rocks area, or winding roads. Be
alert to these and take appropriate action.
385

Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to
pull a trailer are all important. It can also depend
on any special equipment that you have on
your vehicle, and the amount of tongue weight the
vehicle can carry. See “Weight of the Trailer
Tongue” later in this section for more information.Maximum trailer weight is calculated assuming
only the driver is in the tow vehicle and it has all
the required trailering equipment. The weight
of additional optional equipment, passengers and
cargo in the tow vehicle must be subtracted
from the maximum trailer weight.
Use the following chart to determine how much
your vehicle can weigh, based upon your vehicle
model and options.
Vehicle Axle Ratio Maximum Trailer Weight **GCWR
Yukon Denali 3.42 7,400 lbs (3 356 kg) 14,000 lbs (6 350 kg)
Yukon XL Denali 3.42 7,700 lbs (3 493 kg) 14,000 lbs (6 350 kg)
**The Gross Combination Weight Rating (GCWR) in the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be
exceeded.
You can ask your dealer for our trailering
information or advice, or you can write us at the
address listed in your Warranty and Owner
Assistance Information Booklet.In Canada, write to:
General Motors of Canada Limited
Customer Communication Centre, 163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
403

Turn Signals When Towing a Trailer
The arrows on your instrument panel will
ash whenever you signal a turn or lane change.
Properly hooked up, the trailer lamps will also
ash, telling other drivers you’re about to
turn, change lanes or stop.
When towing a trailer, the arrows on your
instrument panel will ash for turns even if the
bulbs on the trailer are burned out. Thus, you may
think drivers behind you are seeing your signal
when they are not. It’s important to check
occasionally to be sure the trailer bulbs are still
working.
Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.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).
You may also want to activate the tow/haul mode
if the transmission shifts too often. See “Tow/Haul
Mode” underTowing a Trailer on page 400.
When towing at high altitude on steep uphill
grades, consider the following: Engine coolant at
or near sea level will boil at a lower temperature
than at higher altitudes. If you turn your engine
off immediately after towing at high altitude
on steep uphill grades, your vehicle may show
signs similar to engine overheating. To avoid this,
let the engine run while parked (preferably on
level ground) with the automatic transmission
in PARK (P) for a few minutes before turning the
engine off. If you do get the overheat warning,
seeEngine Overheating on page 448.
411