2008 GMC ENVOY Owner's Manual

Shifting Into Four-Wheel High or Automatic
Four-Wheel Drive
Turn the knob to Four-Wheel High or Automatic
Four-Wheel Drive. This can be done at any speed
unless you are shifting out of Four-Wheel Low.
The indicator light will ash while shifting. It will
remain on when the shift is complete.
Shifting Into Two-Wheel High
Turn the knob to Two-Wheel High. This can be done at
any speed unless you are shifting out of Four-Wheel Low.
Shifting Into Four-Wheel Low
To shift to Four-Wheel Low, 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
Four-Wheel Low is to have your vehicle moving 1 or
2 mph (1.6 to 3.2 km/h). Turn the knob to Four-Wheel
Low. You must wait for the Four-Wheel Low indicator
light to stop ashing and stay on before shifting the
transmission into gear.
If you turn the knob to Four-Wheel Low when your vehicle
is in gear and/or moving, the Four-Wheel Low indicator
light will ash for 30 seconds and not complete the shiftunless 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 Four-Wheel Low
To shift from Four-Wheel Low to Four-Wheel High, Auto
Four-Wheel Drive, or Two-Wheel High, 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 Four-Wheel
Low is to have your vehicle moving 1 or 2 mph
(1.6 to 3.2 km/h). Turn the knob to Four-Wheel High,
Auto Four-Wheel Drive, or Two-Wheel High. You must
wait for the Four-Wheel High, Auto Four-Wheel Drive, or
Two-Wheel High indicator light to stop ashing and stay
off before shifting your transmission into gear.
If the knob is turned to Four Wheel-High, Auto
Four-Wheel Drive, or Two-Wheel High when your
vehicle is in gear and/or moving, the Four-Wheel High,
Auto Four-Wheel Drive, or Two-Wheel High 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).
2-31

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 Two-Wheel High.
5. Turn the transfer case knob all of the way past
Four-Wheel Low and hold it there for a minimum of
10 seconds. The neutral indicator light will come on.
6. With the engine running, shift the transmission to
REVERSE (R) for one second, then shift the
transmission to DRIVE (D) for one second, to
ensure that the transfer case is in NEUTRAL.
7. Turn the engine off, by turning the key to
ACC/ACCESSORY.
8. Place the transmission shift lever in PARK (P).
9. Turn the ignition to LOCK/OFF.
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. Turn the ignition to ON/RUN with the engine off.
3. Put the transmission in NEUTRAL (N).
4. Turn the transfer case knob to the desired position
(Two-Wheel High, Four-Wheel High, or Auto
Four-Wheel Drive).
5. After the transfer case has shifted out of NEUTRAL,
the indicator light will go out.
6. Release the parking brake.
7. Start the engine and shift the transmission to the
desired position.
2-32

Parking Brake
To set the parking brake,
hold the regular brake
pedal down with your
foot and pull up on
the parking brake lever
located between the seats.
To release the parking brake, hold the regular brake
pedal down. Pull the parking brake lever up until you
can press in the button at the end of the lever. Hold the
button in as you move the parking brake lever all the
way down.If the ignition is on, the brake system warning light on
the instrument panel cluster will come on. SeeBrake
System Warning Light on page 3-38.
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 you must park on a hill,
seeTowing a Trailer on page 4-45.
2-33

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,
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 — not in NEUTRAL. See
Four-Wheel Drive on page 2-29. Always put the
shift lever fully in PARK (P) with the parking
brake rmly set. If you are pulling a trailer,
seeTowing a Trailer on page 4-45.To shift into PARK (P):
1. Hold the brake pedal down with your foot and set
the parking brake.
2. Move the shift lever into PARK (P) by pressing the
button on the side of the shift lever and pushing the
lever all the way toward the front of the vehicle.
3. Turn the ignition key to OFF/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.
2-34

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. SeeFour-Wheel Drive on page 2-29.
And, if you leave the vehicle with the engine
running, it could overheat and even catch re.
You or others could be injured. Do not 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
have 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 was not fully locked into
PARK (P).
Torque Lock
If you are parking on a hill and you do not 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 2-34.
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).
2-35

Shifting Out of PARK (P)
This vehicle has an electronic shift lock release system.
The shift lock release is designed to:
Prevent ignition key removal unless the shift lever
is in PARK (P) with the shift lever button fully
released, and
Prevent movement of the shift lever out of
PARK (P), unless the ignition is in ON/RUN
and the regular brake pedal is applied.
The shift lock release is always functional except in the
case of an uncharged or low voltage (less than 9 volt)
battery.If your vehicle has an uncharged battery or a battery
with low voltage, try charging or jump starting the
battery. SeeJump Starting on page 5-42for more
information.
To shift out of PARK (P) use the following:
1. Apply the brake pedal.
2. Press the shift lever button.
3. Move the shift lever to the desired position.
If you still are unable to shift out of PARK (P):
1. Fully release the shift lever button.
2. Hold the brake pedal down and press the shift lever
button again.
3. Move the shift lever to the desired position.
If you still cannot move the shift lever from PARK (P),
consult your dealer/retailer or a professional towing
service.
2-36

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.
Engine Exhaust
{CAUTION:
Engine exhaust can kill. It contains the gas
carbon monoxide (CO), which you cannot see or
smell. It can cause unconsciousness and death.
CAUTION: (Continued)
CAUTION: (Continued)
You might have exhaust coming in if:
The exhaust system sounds strange or
different.
Your vehicle gets rusty underneath.
Your vehicle was damaged in a collision.
Your vehicle was damaged when driving
over high points on the road or over road
debris.
Repairs were not done correctly.
Your vehicle or the exhaust system has
been modied improperly.
If you ever suspect exhaust is coming into
your vehicle:
Drive it only with all the windows down to
blow out any CO; and
Have your vehicle xed immediately.
2-37

Running the Vehicle While Parked
It is better not to park with the engine running. But if you
ever have to, here are some things to know.
{CAUTION:
Idling the engine with the climate control
system off could allow dangerous exhaust into
your vehicle. See the earlier caution under
Engine Exhaust on page 2-37.
Also, idling in a closed-in place can let deadly
carbon monoxide (CO) into your vehicle even if
the climate control fan is at the highest setting.
One place this can happen is a garage.
Exhaust — with CO — can come in easily.
NEVER park in a garage with the engine
running.
Another closed-in place can be a blizzard.
SeeWinter Driving on page 4-30.
{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. Do not 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 will not move, even
when you are on fairly level ground, always set
the parking brake and move the shift lever to
PARK (P).
2-38