2001 GMC YUKON tow

2-26
4HI: Use 4HI 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.
4LO: This setting also engages your front axle and
delivers extra torque. You may never need 4LO. It sends
maximum power to all four wheels. You might choose
4LO if you are driving off
-road in deep sand, deep mud,
deep snow and climbing or descending steep hills.
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. See ªParking Brakeº in the Index.
NEUTRAL: Shift the vehicle's transfer case to
NEUTRAL only when towing your vehicle. See
ªRecreational Vehicle Towingº or ªTowing Your
Vehicleº in the Index for more information.Indicator lights in the switches show which setting you
are in. The indicator lights will come on briefly 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 flash
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.
If the SERVICE 4WD light stays on, you should take
your vehicle to your dealer for service. See ªService
4WDº in the Index for further information.
Shifting to 4HI or AUTO 4WD
Press and release the 4HI or AUTO 4WD switch. This
can be done at any speed (except when shifting from
4LO), and the indicator light will flash while shifting.
It will remain illuminated when the shift is completed.
Shifting to 2HI
Press and release the 2HI switch. This can be done at
any speed (except when shifting from 4LO).

2-27
Shifting to 4LO
To shift to 4LO, the ignition must be in RUN and the
vehicle must be stopped or moving less than 3 mph
(4.8 km/h) with the transmission in NEUTRAL (N).
The preferred method for shifting into 4LO is to have
your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).
Press and release the 4LO switch. You must wait for the
4LO indicator light to stop flashing and remain
illuminated before shifting your transmission in gear.
If the 4LO switch is pressed when your vehicle is in
gear and/or moving, the 4LO indicator light will flash
for 30 seconds and not complete the shift unless your
vehicle is moving less than 3 mph (4.8 km/h) and the
transmission is in NEUTRAL (N). After 30 seconds the
transfer case will return to the setting last chosen.
Shifting Out of 4LO
To shift from 4LO to 4HI, AUTO 4WD or 2HI your
vehicle must be stopped or moving less than 3 mph
(4.8 km/h) with the transmission in NEUTRAL (N) and
the ignition in RUN. The preferred method for shifting
out of 4LO is to have your vehicle moving 1 to 2 mph
(1.6 to 3.2 km/h). Press and release the 4HI, AUTO
4WD or 2HI switch. You must wait for the 4HI, AUTO
4WD or 2HI indicator light to stop flashing and remain
illuminated before shifting your transmission into gear.If the 4HI, AUTO 4WD or 2HI switch is pressed when
your vehicle is in gear and/or moving, the 4HI, AUTO
4WD or 2HI indicator light will flash for 30 seconds but
will not complete the shift unless your vehicle is moving
less than 3 mph (4.8 km/h) and the transmission is
in NEUTRAL (N).
Shifting to NEUTRAL
To shift the transfer case to NEUTRAL, first make sure
the vehicle is parked so that it will not roll:
1. Set the parking brake.
2. Start the vehicle or turn the ignition to RUN.
3. Connect the vehicle to the towing vehicle.
4. Put the transmission in NEUTRAL (N).
5. Shift the transfer case to 2HI.
6. Simultaneously press and hold the 2HI and
4LO buttons for 10 seconds. The red NEUTRAL
light will come on when the transfer case shift to
NEUTRAL is complete.
7. Shift the transmission to REVERSE (R) for one
second, then shift the transmission to DRIVE (D)
for one second.
8. Turn the ignition to OFF.
9. Place the transmission shift lever in PARK (P).
10. Release the parking brake prior to towing.

2-29
To release the parking brake, hold the regular brake
pedal down. Pull the bottom edge of the lever, located
above the parking brake pedal, marked BRAKE
RELEASE, 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 cause
your rear brakes to overheat. You may have to
replace them, and you could also damage other
parts of your vehicle.
If you are towing a trailer and are parking on any hill,
see ªTowing a Trailerº in the Index. That section shows
what to do first to keep the trailer from moving.
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 firmly 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 won't move, even
when you're 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're pulling
a trailer, see ªTowing a Trailerº in the Index.

2-30
1. Hold the brake pedal down with your right foot and
set the parking brake.
2. Move the shift lever into PARK (P) position like this:

Pull the shift lever toward you.

Move the lever 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).

2-31 Leaving Your Vehicle With the
Engine Running
CAUTION:
It can be dangerous to leave your vehicle with
the engine running. Your vehicle could move
suddenly if the shift lever is not fully in PARK (P)
with the parking brake firmly set. If you have
four
-wheel drive and 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. And, if you leave the vehicle with the
engine running, it could overheat and even catch
fire. You or others could be injured. Don't leave
your vehicle with the engine running unless
you have to.
If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and the
parking brake is firmly set before you leave it. After you
move the shift lever into PARK (P), hold the regular
brake pedal down. Then, see if you can move the shift
lever away from PARK (P) without first pulling it
toward you. If you can, it means that the shift lever
wasn't fully locked into PARK (P).
Torque Lock
If you are parking on a hill and you don't shift your
transmission into PARK (P) properly, the weight of the
vehicle may put too much force on the parking pawl in
the transmission. You may find it difficult to pull the
shift lever out of PARK (P). This is called ªtorque lock.º
To prevent torque lock, set the parking brake and then
shift into PARK (P) properly before you leave the
driver's seat. To find out how, see ªShifting Into
PARK (P)º in the Index.
When you are ready to drive, move the shift lever out of
PARK (P) before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some of the
pressure from the parking pawl in the transmission, so
you can pull the shift lever out of PARK (P).

2-34
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 firmly set. Your vehicle can roll.
Don't leave your vehicle when the engine is
running unless you have to. If you've left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle won't move, even when you're on fairly
level ground, always set your parking brake and
move the shift lever to PARK (P).
Four-wheel drive vehicles with the transfer case
in NEUTRAL will allow the vehicle 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. Always set your parking brake.
Follow the proper steps to be sure your vehicle won't
move. See ªShifting Into PARK (P)º in the Index.
If you're pulling a trailer, see ªTowing a Trailerº in
the Index.
Level Control (If Equipped)
Self-Adjusting
The self
-adjusting rear suspension is available on
C/K 1500 vehicles and is available with the premium
smooth ride suspension package.
This type of level control will provide a leveled riding
position as well as improved handling under a variety of
passenger and loading conditions. A hydraulic pump
inside each rear shock absorber raises the rear of the
vehicle to the proper height, based on inputs from
the road surface, while the vehicle is being driven.
It takes approximately 2 miles (3.2 km) of driving
for the leveling to complete, depending on the road
surface conditions.
If the loaded vehicle is not moved for approximately
twelve hours, the leveling system may bleed down to a
lower height. This can be especially apparent if a trailer
is left attached to a parked vehicle for long periods of
time. The vehicle must be driven to re
-level the vehicle.
If a self
-equalizing hitch is being used, the vehicle
should be driven approximately 2 miles (3.2 km) with
the trailer prior to adjusting (leveling) the hitch.

2-35
Automatic Level Control
The automatic level control rear suspension is available
on C/K 1500 vehicles and comes as a part of the
Autoride
suspension.
This type of level control is fully automatic and will
provide a better leveled riding position as well as better
handling under a variety of passenger and loading
conditions. An air compressor connected to the rear
shocks will raise or lower the rear of the vehicle to
maintain proper vehicle height. The system is activated
when the ignition key is turned to RUN and will
automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for
up to ten minutes after the ignition key has been
turned to OFF. You may hear the air compressor
operating when the height is being adjusted.
If a self
-equalizing hitch is being used, it is
recommended to allow the shocks to inflate, thereby
leveling the vehicle prior to adjusting the hitch.
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/drive 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. See ªTow/Haul Modeº in
the Index for more information.
Locking Rear Axle
If your vehicle has this feature, your locking rear axle
can give you additional traction on snow, mud, ice, sand
or gravel. It works like a standard axle most of the time,
but when one of the rear wheels has no traction and the
other does, this feature will allow the wheel with
traction to move the vehicle.

2-38 Headlamp High/Low Beam Changer
To change the headlamps from low to high beam or high
to low beam, pull the multifunction lever all the way
toward you. Then release it.
When the high beams
are on, this light on the
instrument panel also
will be on.
Flash-To-Pass Feature
This feature allows you to use your high-beam
headlamps to signal a driver in front of you that you
want to pass. It works even if your headlamps are off.
To use it, pull the turn signal lever toward you, but not
so far that you hear it click.
If your headlamps are off or on low
-beam, your
high
-beam headlamps will turn on. They'll stay on as
long as you hold the lever toward you and the
high
-beam indicator on the instrument panel will
come on. Release the lever to turn the high
-beam
headlamps off.
Windshield Wipers
You control the windshield wipers by turning the band
with the wiper symbol on it.
For a single wiping cycle, turn the band to MIST. Hold
it there until the wipers start, then let go. The wipers will
stop after one wipe. If you want more wipes, hold the
band on MIST longer.
You can set the wiper speed for a long or short delay
between wipes. This can be very useful in light rain or
snow. Turn the band to choose the delay time.
The closer to LO, the shorter the delay.