wheel GMC SIERRA 2001 User Guide

2-25
CAUTION: (Continued)
If you have four-wheel drive, your vehicle
will be free to roll
-- even if your shift lever
is in PARK (P)
-- if your transfer case is in
NEUTRAL. So, be sure the transfer case is in a
drive gear, two
-wheel high (2H) or four-wheel
high (4H) or four
-wheel low (4L) -- not in
NEUTRAL. See ªShifting Into PARK (P)º in the
Index. If you're pulling a trailer, see ªTowing a
Trailerº in the Index.
REVERSE (R): Use this gear to back up. If your vehicle
is equipped with the Allison Transmission, the ªRº may
blink on the PRNDL if the shift inhibitor is active.
NOTICE:
Shifting to REVERSE (R) while your vehicle is
moving forward could damage your transmission.
Shift to REVERSE (R) only after your vehicle
is stopped. If your vehicle is equipped with
the Allison Transmission, do not idle in
REVERSE (R) for more than five minutes.
Extended idling in REVERSE (R) may cause
transmission overheating and damage. Always
select PARK (P) whenever idle time exceeds
five minutes.
To rock your vehicle back and forth to get out of snow,
ice or sand without damaging your transmission, see
ªStuck: In Sand, Mud, Ice or Snowº in the Index.

2-26
NEUTRAL (N): In this position, your engine doesn't
connect with the wheels. To restart when you're already
moving, use NEUTRAL (N) only. Also, use
NEUTRAL (N) when your vehicle is being towed.
CAUTION:
Shifting out of PARK (P) or NEUTRAL (N) while
your engine is ªracingº (running at high speed) is
dangerous. Unless your foot is firmly on the
brake pedal, your vehicle could move very
rapidly. You could lose control and hit people
or objects. Don't shift out of PARK (P) or
NEUTRAL (N) while your engine is racing.
NOTICE:
Damage to your transmission caused by shifting
out of PARK (P) or NEUTRAL (N) with the
engine racing isn't covered by your warranty.
DRIVE (D): This position is for normal driving. If you
need more power for passing, and you're:

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.
You'll shift down to the next gear and have more power.
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
THIRD (3) or, if necessary, a lower gear selection if
the transmission shifts too often.
NOTICE:
If your vehicle is equipped with the Allison
Transmission, do not idle in DRIVE (D) for more
than five minutes. Extended idling in DRIVE (D)
may cause transmission overheating and damage.
Always select PARK (P) if idle time is longer than
five minutes.

2-27
If your vehicle is equipped with the Allison Transmission,
it will initially attain first range when DRIVE (D) is
selected. As vehicle speed increases, the transmission
will upshift automatically through each available range
up to FIFTH (5). As the vehicle slows, the transmission
will downshift automatically.
THIRD (3): This position is also used for normal
driving, however it offers more power and lower fuel
economy than DRIVE (D).
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
selector lever is put in FIRST (1) while the vehicle is
moving forward, the transmission won't shift into
first gear until the vehicle is going slowly enough.
NOTICE:
If your rear wheels can't rotate, don't try to
drive. This might happen if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don't hold
your vehicle there with only the accelerator
pedal. This could overheat and damage the
transmission. Use your brakes or shift into
PARK (P) to hold your vehicle in position
on a hill.
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.

2-33
If your engine speed drops below 600 rpm, or if the
engine is not running smoothly, you should downshift to
the next lower gear. When operating on slippery
surfaces, downshift at lower than normal vehicle speeds
to prevent the tires from slipping.
In bench seat equipped vehicles, move the tallest
beverage containers to the right cupholder to provide
additional clearance for the shift lever.
For vehicles equipped with a center console, the front
cup holder pulls out and turns 180
to provide additional
clearance between tall beverage containers and the
shift lever.Shift Light
If you have a manual
transmission, you may have
a SHIFT light. This light
will show you when to shift
to the next higher gear for
best fuel economy.
When this light comes on, you can shift to the next
higher gear if weather, road and traffic conditions allow.
For the best fuel economy, accelerate slowly and shift
when the light comes on.
While you accelerate, it is normal for the light to go on and
off if you quickly change the position of the accelerator.
If your vehicle has four
-wheel drive and is equipped
with a manual transmission, disregard the SHIFT light
when the transfer case is in 4
-Wheel Low.
Ignore the SHIFT light when you downshift.

2-34
Four-Wheel Drive (If Equipped)
If your vehicle has four-wheel drive, 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. See the
appropriate text for the transfer case in your vehicle.
NOTICE:
Driving in the 4-WHEEL HIGH (4HI) or
4
-WHEEL LOW (4LO) positions for a long time
on dry or wet pavement could shorten the life of
your vehicle's drivetrain.
Front Axle Locking Feature
The front axle locks and unlocks automatically when
you shift the transfer case. Some delay for the axle to
lock or unlock is normal.
Manual Transfer Case (If Equipped)
The transfer case shift lever is on the floor to the right of the
driver. Use this lever to shift into and out of four
-wheel drive.
The 4WD indicator will
light up when you shift into
four
-wheel drive and the
front axle engages.
Some delay between shifting and the indicator's lighting
is normal.

2-35
An indicator on the bezel near the lever shows you the
transfer case settings:
2
-Wheel High (2HI): 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
-Wheel High (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.
CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the transmission
is in PARK (P), or if you have a manual
transmission, even if you are in gear. 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 (N): Shift to this setting only when your
vehicle needs to be towed. The ignition switch must be
in RUN in order to shift the lever into NEUTRAL (N).
See ªRecreational Vehicle Towingº or ªTowing your
Vehicleº in the Index.
4
-Wheel Low (4L0): 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.

2-36
You can shift from 2-Wheel High (2HI) to
4
-Wheel High (4HI) or from 4-Wheel High (4HI) to
2
-Wheel High (2HI) while the vehicle is moving. Your
front axle will engage faster if you take your foot off of
the accelerator for a couple of seconds after you shift.
In extremely cold weather, it may be necessary to stop
or slow the vehicle to shift into 4
-Wheel High (4HI).
To shift into or out of 4
-Wheel Low (4LO)
or NEUTRAL (N):
1. Slow the vehicle to a roll, about 1 to 3 mph
(2 to 5 km/h) and shift an automatic transmission
into NEUTRAL (N), or with a manual transmission,
press the clutch pedal.
2. Shift the transfer case shift lever in
one continuous motion.
Don't pause in NEUTRAL (N) as you shift the transfer
case into 4
-Wheel Low (4LO), or your gears could clash.
Remember that driving in 4
-Wheel High (4HI) or
4
-Wheel Low (4LO) may reduce fuel economy. Also,
driving in four
-wheel drive on dry pavement could
cause your tires to wear faster and make your transfer
case harder to shift and run noisier.
Automatic Transfer Case (If Equipped)
The transfer case switches
are located to the left of the
instrument panel cluster.
Use these switches to shift into and out of four
-wheel drive.

2-37
You can choose among four driving settings:
2HI: 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.
AUTO 4WD: This setting is ideal for use when road
conditions are variable. When driving your vehicle in
AUTO 4WD, the front axle is engaged, but the vehicle's
power is sent 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 2HI.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.

2-40
Electronic Transfer Case (If Equipped)
If your four-wheel-drive vehicle has the electronic
transfer case, the transfer case switches are located to
the left of the instrument panel cluster.
Use these switches to shift into and out of four
-wheel
drive. You can choose among three driving settings:
2HI: This setting is for driving in most street and
highway situations. Your front axle is not engaged in
two
-wheel drive.
4HI: This setting engages your front axle to help drive
your vehicle. Use 4HI when you need extra traction, such
as on snowy or icy roads, or in most off
-road situations.
4LO: This setting also engages your front axle to give
you extra traction. You may never need 4LO. It sends
the maximum power to all four wheels. You might
choose 4LO if you were driving off
-road in sand, mud
or deep snow and climbing or descending steep hills.
Indicator lights in the switches show you which setting
you are in. The indicator lights will come on briefly
when you turn on the ignition and the last chosen setting
will stay on. If the lights do not come on, you should
take your vehicle in for service. An indicator light will
flash while shifting. It will remain illuminated when the
shift is completed. If for some reason the transfer
cannot make a requested shift, it will return to the last
chosen setting.

2-44
Shifting Into PARK (P)
(Automatic Transmission Only)
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.
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.