2003 GMC ENVOY tow

Automatic Transmission Operation
There are several different positions for your gear
shift lever.
PARK (P):This position locks the rear wheels. It's the
best position to use when you start the engine
because your vehicle can't move easily.
{CAUTION:
It is 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.
Don't leave your vehicle when the engine is
running unless you have to. 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, always set your
parking brake and move the shift lever to
PARK (P). See ªShifting Into Park (P)º in the
Index. If you're pulling a trailer, see ªTowing a
Trailerº in the Index.
{CAUTION:
If you have four-wheel drive, your vehicle will
be free to roll Ð even if your shift lever is in
PARK (P) Ð if your transfer case is in
NEUTRAL. So, be sure the transfer case is in a
drive gear Ð not in NEUTRAL. See
ªFour-Wheel Drive (Automatic Transfer Case)º
in the Index. See ªShifting Into Park (P)º in
the Index.
Ensure the shift lever is fully in PARK (P) before starting
the engine. Your vehicle has an automatic transmission
shift lock control system. You have to fully apply the
regular brakes before you can shift from PARK (P) when
the ignition key is in RUN. If you cannot shift out of
PARK (P), ease pressure on the shift lever, press the
button on the shift lever and push the shift lever all
the way into PARK (P) as you maintain brake
application. Move the shift lever into the gear you wish.
See
Shifting Out of Park (P) on page 2-31.
2-23

REVERSE (R):Use this gear to back up.
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.
To rock your vehicle back and forth to get out of snow,
ice or sand without damaging your transmission,
see If You Are Stuck: In Sand, Mud, Ice or Snow on
page 4-44.
NEUTRAL (N):In this position, the engine doesn't
connect with the wheels. To restart when you're already
moving, use NEUTRAL (N) only.
{CAUTION:
Shifting into a drive gear while your engine is
ªracingº (running at high speed) is dangerous.
Unless your foot is ®rmly on the brake pedal,
your vehicle could move very rapidly. You
could lose control and hit people or objects.
Don't shift into a drive gear 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.On cold days, about 32É F (0ÉC) or colder, your
transmission is designed to shift differently until the
engine reaches normal operating temperature. This is
intended to improve heater performance.
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 the
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.
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 than THIRD (3). 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 the brakes off and on.
You can also use SECOND (2) for starting the vehicle
from a stop on slippery road surfaces.
2-24

4HI (Four-Wheel High):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.
4LO (Four-Wheel Low):This setting also engages
your front axle and delivers extra torque. It sends
maximum power to all four wheels. You might choose
4LO if you are driving off-road in deep sand, deep mud,
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
Recreational Vehicle Towing on page 4-45for more
information.An indicator light in the knob will show you which
position the transfer case is in. The indicator lights will
come on brie¯y 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.
If the service four-wheel drive light on the instrument
panel cluster stays on, you should take your vehicle to
your dealer for service. See
Service Four-Wheel
Drive Warning Light on page 3-48for further information.
Shifting into 4HI or A4WD
Turn the knob to 4HI or A4WD. This can be done at any
speed unless you are shifting out of 4LO. The indicator
light will ¯ash while shifting. It will remain illuminated
when the shift is complete.
Shifting into 2HI
Turn the knob to 2HI. This can be done at any speed
unless you are shifting out of 4LO.
2-26

Shifting into 4LO
To shift to 4LO, the vehicle's engine must be running
and the vehicle must be stopped or moving less
than 2 mph (3.2 km/h) with the transmission in
NEUTRAL (N). The preferred method for shifting into
4LO is to have your vehicle moving 1 or 2 mph (1.6 to
3.2 km/h). Turn the knob to 4LO. You must wait for
the 4LO indicator light to stop ¯ashing and remain
illuminated before shifting your transmission into gear.
If you turn the knob to 4LO when your vehicle is in gear
and/or moving, the 4LO indicator light will ¯ash for
30 seconds and not complete the shift unless your
vehicle is moving less than 2 mph (3.2 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, A4WD or 2HI your vehicle
must be stopped or moving less than 2 mph (3.2 km/h)
with the transmission in NEUTRAL (N) and the
engine running. The preferred method for shifting out of
4LO is to have your vehicle moving 1 or 2 mph (1.6
to 3.2 km/h). Turn the knob to 4HI, A4WD or 2HI. You
must wait for the 4HI, A4WD or 2HI indicator light to stop
¯ashing and remain illuminated before shifting your
transmission into gear.If the knob is turned to 4HI, A4WD or 2HI when your
vehicle is in gear and/or moving, the 4HI, A4WD or 2HI
indicator light will ¯ash for 30 seconds. It will not
complete the shift unless your vehicle is moving less
than 2 mph (3.2 km/h) with the transmission in
NEUTRAL (N).
Shifting into NEUTRAL
Before shifting the transfer case to NEUTRAL, ®rst
make sure the vehicle is parked so that it will not roll.
1. Set the parking brake.
2. Start the vehicle.
3. Put the transmission in NEUTRAL (N).
4. Shift the transfer case to 2HI.
5. Turn the transfer case knob all of the way past 4LO
and hold it there for a minimum of 10 seconds. The
neutral indicator light will come on.
6. Shift the transmission to REVERSE (R) for one
second, then shift the transmission to DRIVE (D)
for one second.
7. Place the transmission shift lever in PARK (P).
8. Release the parking brake prior to towing.
9. Turn the ignition to LOCK.
2-27

Notice:Driving with the parking brake on can
cause your parking brake 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 you must park on a hill,
see
Towing a Trailer on page 4-50. That section
shows what to do ®rst 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 ®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 won't
move, even when you're on fairly level ground,
CAUTION: (Continued)
CAUTION: (Continued)
use the steps that follow. With four-wheel
drive, your vehicle will be free to roll Ð even if
your shift lever is in PARK (P) Ð if your
transfer case is in NEUTRAL. So, be sure the
transfer case is in a drive gear Ð not in
NEUTRAL. See ªFour-Wheel Driveº in the
Index. Always put the shift lever fully in
PARK (P) with the parking brake ®rmly set. If
you're pulling a trailer, see ªTowing a Trailerº
in the Index.
To shift into PARK (P), do the following:
1. Hold the brake pedal down with your right foot and
set the parking brake.
2-29

2. Move the shift lever into PARK (P) like this:
2.1. Press the button in on the side of the lever.
2.2. Push the lever all the way toward the
front of the vehicle.
3. Turn the ignition key to LOCK.
4. Remove the key and take it with you. You know
your vehicle is in PARK (P) if the key can be
removed from the ignition.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 ®rmly set.
If you have four-wheel drive, your vehicle
will be free to roll ± even if your lever is in
PARK (P) ± if your transfer case is in
NEUTRAL. So be sure the transfer case is in a
drive gear ± not NEUTRAL. See ªFour-Wheel
Drive (Automatic Transfer Case)º in the Index.
And, if you leave the vehicle with the engine
running, it could overheat and even catch ®re.
You or others could be injured. Don't leave
your vehicle with the engine running unless
you have to.
2-30

{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. 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).
{CAUTION:
If you have four-wheel drive, your vehicle will
be free to roll Ð even if your shift lever is in
PARK (P) Ð if your transfer case is in
NEUTRAL. So be sure the transfer case is in a
drive gear Ð not in NEUTRAL. See
ªFour-Wheel Drive (Automatic Transfer case)º
in the Index.
Follow the proper steps to be sure your vehicle won't
move. See
Shifting Into Park (P) on page 2-29.
If you're pulling a trailer, see
Towing a Trailer on
page 4-50.
2-34

Outside Manual Mirrors
Adjust your outside mirrors so you can see a little of the
side of your vehicle.
Fold the mirrors in before entering a car wash. To do
this, pull the mirrors in toward the vehicle. Push the
mirrors back out when ®nished.
Outside Power Mirrors
Your vehicle may have this feature.The control is located on the driver's door.
1. Twist the knob toward the mirror you desire to
adjust.
2. Move the knob in the direction you want the mirror
to go.
3. Adjust the mirror in all four directions.
4. After you are satis®ed with the position of the
mirror, twist the knob to the center position or twist it
to the other mirror to adjust that mirror.
If you reach the mirror's end of the travel position in any
direction, the mirror will enter a ratcheting mode. This
action is harmless. It is a warning that the mirror can go
no further. To stop this action, back the mirror up by
moving the knob in the opposite direction.
When the knob is twisted to the center position, the
mirrors can not be moved with the control knob.
2-37