2006 GMC YUKON Owner's Manual

SECOND (2):This position gives you more power
but lower fuel economy. You can use SECOND (2) on
hills. It can help control your speed as you go down
steep mountain roads, but then you would also want
to use your brakes off and on.
If you manually select SECOND (2) in a light duty
automatic transmission, the transmission will drive in
second gear. You may use this feature for reducing the
speed of the rear wheels when you are trying to start
your vehicle from a stop on slippery road surfaces.
FIRST (1):This position gives you even more
power (but lower fuel economy) than SECOND (2).
You can use it on very steep hills, or in deep snow or
mud. If the shift lever is put in FIRST (1) while the
vehicle is moving forward, the transmission will not shift
into rst gear until the vehicle is going slowly enough.
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.
On cold days, approximately 32°F (0°C) or colder,
your transmission is designed to shift differently until
the engine reaches normal operating temperature.
This is intended to improve heater performance.Tow/Haul Mode
Your vehicle may be equipped with a Tow/Haul mode.
If so, the selector button is located on the end of the
column shift lever. You can use this feature to assist
when towing or hauling a heavy load. SeeTowing a
Trailer on page 4-60for more information.
2-25

When Tow/Haul mode
is selected the
Tow/Haul indicator
light will illuminate.
The Tow/Haul mode also interacts with the Autoride
®
feature, if equipped, to enhance the ride when trailering
or with a loaded vehicle. SeeAutoride®on page 4-60.
Four-Wheel Drive
If your vehicle has four-wheel drive, you will see the
buttons shown below. You can send your engine’s
driving power to all four wheels for extra traction.
To get the most satisfaction out of four-wheel drive,
you must be familiar with its operation. Read the
part that follows before using four-wheel drive.
Notice:Driving on clean, dry pavement in
Four-Wheel-Drive High or Four-Wheel-Drive Low for
an extended period of time may cause premature
wear on your vehicle’s powertrain. Do not drive on
clean, dry pavement in Four-Wheel Drive High or
Four-Wheel-Drive Low for extended periods of time.The transfer case buttons
are located to the left
of the instrument panel
cluster.
The front axle locks and unlocks automatically when
you shift the transfer case. Some delay for the axle
to lock or unlock is normal.
For information on StabiliTrak
®, seeStabiliTrak®
System on page 4-9.
Use these buttons to shift into and out of
four-wheel drive.
2-26

You can choose among four driving settings:
AUTO 4WD (Automatic Four-Wheel Drive):This
setting is ideal for use when road surface traction
conditions are variable. When driving your vehicle in
AUTO 4WD, the front axle is engaged, but the vehicle’s
power is sent only to the rear wheels. When the
vehicle senses a loss of traction, the system will
automatically engage four-wheel drive. Driving in this
mode results in slightly lower fuel economy than
Two-Wheel High.
2
m(Two-Wheel High):This setting is used for driving
in most street and highway situations. Your front axle
is not engaged in two-wheel drive. This setting also
provides the best fuel economy.
4
m(Four-Wheel High):Use the four-wheel high
position when you need extra traction, such as on snowy
or icy roads or in most off-road situations. This setting
also engages your front axle to help drive your vehicle.
This is the best setting to use when plowing snow.
4
n(Four-Wheel Low):This setting also engages
your front axle and delivers extra torque. You may
never need this setting. It sends maximum power to all
four wheels. You might choose Four Wheel-Low if you
are driving off-road in deep sand, deep mud, deep snow,
and while climbing or descending steep hills. StabiliTrak
®
will not engage in this mode. SeeStabiliTrak®System
on page 4-9for more information.
{CAUTION:
Shifting the transfer case to NEUTRAL
can cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to
set the parking brake before placing the
transfer case in NEUTRAL. SeeParking
Brake on page 2-31.
NEUTRAL (N):Shift the vehicle’s transfer case
to NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-56orTowing
Your Vehicle on page 4-56for more information.
Indicator lights in the button show which setting you
are in. The indicator lights will come on briey when
you turn on the ignition and one will stay on. If the
lights do not come on, you should take your vehicle
to your dealer for service. An indicator light will
ash while shifting the transfer case. It will remain
illuminated when the shift is complete. If for some
reason the transfer case cannot make a requested
shift, it will return to the last chosen setting.
2-27

If the SERVICE 4WD message stays on, you should
take your vehicle to your dealer for service. See “Service
4WD message” underDIC Warnings and Messages
on page 3-56.
Shifting Into Four-Wheel High or
AUTO 4WD (Automatic Four-Wheel Drive)
Press and release the Four-Wheel High or AUTO
4WD button. This can be done at any speed, except
when shifting from Four-Wheel Low, and the indicator
light will ash while shifting. It will remain on when
the shift is completed.
Shifting Into Two-Wheel High
Press and release the Two-Wheel High button.
This can be done at any speed, except when
shifting from Four-Wheel Low.
Shifting Into Four-Wheel Low
To shift to the Four-Wheel Low position, the ignition
must be in RUN and the vehicle must be stopped
or moving less than 3 mph (5 km/h) with the
transmission in NEUTRAL (N). The preferred
method for shifting into four-wheel low is to have
your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).Press and release the Four-Wheel Low button.
You must wait for the four-wheel low indicator light
to stop ashing and remain on before shifting your
transmission in gear.
Notice:Shifting the transmission into gear before
the Four-Wheel Low indicator light has stopped
ashing could damage the transfer case. To
help avoid damaging your vehicle, always wait for
the Four-Wheel Low indicator light to stop ashing
before shifting the transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting between
Four-Wheel Low and Four-Wheel High ranges or from
NEUTRAL with the engine running.
If the Four-Wheel Low button is pressed when your
vehicle is in gear and/or moving, the Four-Wheel Low
indicator light will ash for 30 seconds and not complete
the shift unless your vehicle is moving less than
3 mph (5 km/h) and the transmission is in NEUTRAL (N).
After 30 seconds the transfer case will shift to
Four-Wheel High mode.
2-28

Shifting Out of Four-Wheel Low
To shift from Four-Wheel Low to Four-Wheel High,
AUTO 4WD or Two-Wheel High, your vehicle must be
stopped or moving less than 3 mph (5 km/h) with the
transmission in NEUTRAL (N) and the ignition in RUN.
The preferred method for shifting out of Four-Wheel
Low is to have your vehicle moving 1 to 2 mph
(1.6 to 3.2 km/h). Press and release the Four-Wheel
High, AUTO 4WD or Two-Wheel High button. You must
wait for the Four-Wheel High, AUTO 4WD or Two-Wheel
High indicator light to stop ashing and remain on
before shifting your transmission into gear.
Notice:Shifting the transmission into gear before
the Four-Wheel Low indicator light has stopped
ashing could damage the transfer case. To help
avoid damaging your vehicle, always wait for the
Four-Wheel Low indicator light to stop ashing
before shifting the transmission into gear.It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting between
Four-Wheel Low and Four-Wheel High ranges or from
NEUTRAL with the engine running.
If the Four-Wheel High, AUTO 4WD or Two-Wheel High
switch is pressed when your vehicle is in gear and/or
moving, the Four-Wheel High, AUTO 4WD or Two-Wheel
High indicator light will ash for 30 seconds but will not
complete the shift unless your vehicle is moving less than
3 mph (5 km/h) and the transmission is in NEUTRAL (N).
2-29

Shifting into NEUTRAL
To shift the transfer case to NEUTRAL do the following:
1. Make sure the vehicle is parked so that it will
not roll.
2. Set the parking brake. SeeParking Brake on
page 2-31for more information.
3. Start the vehicle or turn the ignition to RUN.
4. Put the transmission in NEUTRAL (N).
5. Shift the transfer case to Two-Wheel High.
6. Simultaneously press and hold the Two-Wheel High
and Four-Wheel Low buttons for 10 seconds.
The NEUTRAL light will come on when the transfer
case shift to NEUTRAL is complete.
7. If the engine is running, verify that the transmission
is in NEUTRAL (N) by shifting the transmission
to REVERSE (R) for one second, then shift
the transmission to DRIVE (D) for one second.
8. Turn the ignition to ACCESSORY, which will turn
the engine off.
9. Place the transmission shift lever in PARK (P).
10. Turn the ignition to LOCK.
Shifting Out of NEUTRAL
To shift out of NEUTRAL do the following:
1. Set the parking brake and apply the regular
brake pedal.
2. Shift the transmission to NEUTRAL (N) and turn
the ignition to RUN with the engine off.
3. Press the button for the desired transfer case
shift position (Two-Wheel High, Four-Wheel High,
AUTO 4WD, or Four-Wheel Low).
After the transfer case has shifted out of
NEUTRAL the NEUTRAL light will go out.
4. Release the parking brake.
Notice:Shifting the transmission into gear
before the Four-Wheel Low indicator light has
stopped ashing could damage the transfer case.
To help avoid damaging your vehicle, always
wait for the Four-Wheel Low indicator light to stop
ashing before shifting the transmission into gear.
5. Start the engine and shift the transmission to
the desired position.
Excessively shifting the transfer case into or out of
the different modes may cause the transfer case to enter
the shift protection mode. This will protect the transfer
case from possible damage and will only allow the
transfer case to respond to one shift per 10 seconds.
The transfer case may stay in this mode for up to
three minutes.
2-30

Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking
brake pedal with your left foot.
A chime will activate and the warning light will ash
when the parking brake is applied and the vehicle
is moving at least 3 mph (5 km/h) for at least
three seconds.
To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge of the lever, located
above the parking brake pedal, with the parking
brake symbol, to release the parking brake.If the ignition is on when the parking brake is released,
the brake system warning light will go off.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Verify that
the parking brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and are parking on any hill,
seeTowing a Trailer on page 4-60.
2-31

Shifting Into Park (P)
{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with
the parking brake rmly set. Your vehicle can
roll. If you have left the engine running, the
vehicle can move suddenly. You or others
could be injured. To be sure your vehicle
will not move, even when you are on fairly
level ground, use the steps that follow.
With four-wheel drive, if your transfer case
is in NEUTRAL, your vehicle will be free to
roll, even if your shift lever is in PARK (P).
So, be sure the transfer case is in a drive
gear — not in NEUTRAL. If you are pulling
a trailer, seeTowing a Trailer on page 4-60.1. Hold the brake pedal down with your right foot
and set the parking brake.
2. Move the shift lever into the PARK (P) position
by pulling the shift lever toward you and moving
it up as far as it will go.
3. Be sure the transfer case is in a drive
gear — not in NEUTRAL (N).
4. Turn the ignition key to LOCK.
5. Remove the key and take it with you. If you
can leave your vehicle with the ignition key in
your hand, your vehicle is in PARK (P).
2-32