2004 GMC ENVOY transmission

Automatic Transfer Case
If your vehicle is equipped
with four-wheel drive, the
transfer case knob is
located to the right of the
steering wheel on the
instrument panel. Use this
knob to shift into and
out of four-wheel drive.
2HI (Two-Wheel High):This setting is for driving in
most street and highway situations. Your front axle is not
engaged in two-wheel drive. It also provides the best
fuel economy.
A4WD (Automatic Four-Wheel Drive):This setting is
ideal for use when road conditions are variable.
When driving your vehicle in A4WD, 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 (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. SeeParking Brake on
page 2-30.
NEUTRAL:Shift the vehicle’s transfer case to
NEUTRAL only when towing your vehicle. See
Recreational Vehicle Towing on page 4-44for more
information.
2-27

An indicator light in the knob will show you which
position the transfer case is 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.
If the service four-wheel drive light on the instrument
panel cluster stays on, you should take your vehicle to
your dealer for service. SeeService Four-Wheel
Drive Warning Light on page 3-47for 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.
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 into4LO 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).
2-28

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. Turn the ignition to LOCK.
9. Release the parking brake prior to towing.
Shifting Out of NEUTRAL
To shift the transfer case out of NEUTRAL, do the
following:
1. Set the parking brake and apply the regular brake
pedal.
2. Start the vehicle with the transmission in PARK (P).
3. Turn the transfer case knob to the desired shift
position (2HI, 4HI or A4WD).
4. Put the transmission in NEUTRAL (N).
5. Release the parking brake.
6. After the transfer case has shifted out of NEUTRAL,
the indicator light will go out. Shift the transmission
lever to the desired position.
A re-engagement sound is normal when shifting out of
NEUTRAL.
2-29

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 “Four-Wheel Drive
(Automatic Transfer Case)” 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.If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and your
parking brake is rmly set before you leave it. After
you’ve moved 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 rst
pressing the button on the console shift lever. 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 nd it difficult to pull the
shift lever out of PARK (P). This is called “torque
lock.” To prevent torque lock, set the parking brake and
then shift into PARK (P) properly before you leave
the driver’s seat. To nd out how, seeShifting Into Park
(P) on page 2-31.
When you are ready to drive, move the shift lever out of
PARK (P)beforeyou 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).
2-32

Shifting Out of Park (P)
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 is in RUN. SeeAutomatic Transmission
Operation on page 2-24.
Parking Over Things That Burn
{CAUTION:
Things that can burn could touch hot exhaust
parts under your vehicle and ignite. Do not
park over papers, leaves, dry grass or other
things that can burn.
2-33

This device complies with RSS- 210 of Industry Canada.
Operation is subject to the following two conditions:
(1) this device may not cause interference, and (2) this
device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes and modications to this system by other than
an authorized service facility could void authorization
to use this equipment.
Programming the HomeLink®
Transmitter
Do not use the HomeLink®Transmitter with any garage
door opener that does not have the “stop and reverse”
feature. This includes any garage door opener model
manufactured before April 1, 1982. If you have a newer
garage door opener with rolling codes, please be
sure to follow steps 6 through 8 to complete the
programming of your HomeLink
®Transmitter.
Read the instructions completely before attempting to
program the HomeLink
®Transmitter. Because of
the steps involved, it may be helpful to have another
person available to assist you in programming the
transmitter.Keep the original transmitter for use in other vehicles as
well as for future HomeLink
®programming. It is also
recommended that upon the sale of the vehicle,
the programmed HomeLink
®buttons should be erased
for security purposes. Refer to “Erasing HomeLink®
Buttons” or, for assistance, contact HomeLink®on the
internet at: www.homelink.com or by calling
1-800-355-3515.
Be sure that people and objects are clear of the garage
door or gate operator you are programming. When
programming a garage door, it is advised to park outside
of the garage.
It is recommended that a new battery be installed in
your hand-held transmitter for quicker and more
accurate transmission of the radio frequency.
Your vehicle’s engine should be turned off while
programming the transmitter. Follow these steps to
program up to three channels:
1. Press and hold down the two outside buttons,
releasing only when the indicator light begins to
ash, after 20 seconds. Do not hold down the
buttons for longer than 30 seconds and do not
repeat this step to program a second and/or third
transmitter to the remaining two HomeLink
®buttons.
2. Position the end of your hand-held transmitter about
1 to 3 inches (3 to 8 cm) away from the HomeLink
®
buttons while keeping the indicator light in view.
2-42

Gate Operator and Canadian
Programming
Canadian radio-frequency laws require transmitter
signals to “time out” or quit after several seconds of
transmission. This may not be long enough for
HomeLink
®to pick up the signal during programming.
Similarly, some U.S. gate operators are manufactured to
“time out” in the same manner.
If you live in Canada, or you are having difficulty
programming a gate operator by using the
“Programming HomeLink
®” procedures (regardless of
where you live), replace Step 3 under “Programming
HomeLink
®” with the following:
Continue to press and hold the HomeLink
®button while
you press and release every two seconds (cycle)
your hand-held transmitter until the frequency signal has
been successfully accepted by HomeLink
®. The
indicator light will ash slowly at rst and then rapidly.
Proceed with Step 4 under “Programming HomeLink
®”
to complete.
Using HomeLink®
Press and hold the appropriate HomeLink®button for at
least half of a second. The indicator light will come
on while the signal is being transmitted.
Erasing HomeLink®Buttons
To erase programming from the three buttons do the
following:
1. Press and hold down the two outside buttons until
the indicator light begins to ash, after 20 seconds.
2. Release both buttons. Do not hold for longer than
30 seconds.
HomeLink
®is now in the train (learning) mode and can
be programmed at any time beginning with Step 2
under “Programming HomeLink
®.”
Individual buttons can not be erased, but they can be
reprogrammed. See “Reprogramming a Single
HomeLink
®Button” next.
2-44

Increasing Speed While Using Cruise
Control
There are two ways to go to a higher speed:
Use the accelerator pedal to get to the higher
speed. Press the button at the end of the lever,
then release the button and the accelerator pedal.
You’ll now cruise at the higher speed.
Move the cruise switch from on to
resume/accelerate. Hold it there until you get up to
the speed you want, and then release the switch.
To increase your speed in very small amounts,
move the switch briey to resume/accelerate.
Each time you do this, your vehicle will go about
1 mph (1.6 km/h) faster.
Reducing Speed While Using Cruise
Control
Press in the set button at the end of the lever until you
reach the lower speed you want, then release it.
Each time you do this, you’ll go about 1 mph (1.6 km/h)
slower.
Passing Another Vehicle While Using
Cruise Control
Use the accelerator pedal to increase your speed.
When you take your foot off the pedal, your vehicle will
slow down to the cruise control speed you set earlier.
Using Cruise Control on Hills
How well your cruise control will work on hills depends
upon your speed, load and the steepness of the
hills. When going up steep hills, you may want to step
on the accelerator pedal to maintain your speed.
When going downhill, you may have to brake or shift to
a lower gear to keep your speed down. Of course,
applying the brake takes you out of cruise control. Many
drivers nd this to be too much trouble and don’t use
cruise control on steep hills.
Ending Cruise Control
There are three ways to turn off the cruise control:
Step lightly on the brake pedal.
Move the cruise switch to off, or
Shift the transmission to NEUTRAL (N).
Erasing Speed Memory
When you turn off the cruise control or the ignition, your
cruise control set speed memory is erased.
3-14