2004 GMC ENVOY XL engine

When starting your engine in very cold weather
(below 0°F or−18°C), do this:
1. With your foot off the accelerator pedal, turn
the ignition key to START and hold it there up
to 15 seconds. When the engine starts, let go
of the key.
2. If your engine still won’t start (or starts but then
stops), it could be ooded with too much gasoline.
Try pushing your accelerator pedal all the way to the
oor and holding it there as you hold the key in
START for about three seconds. When the engine
starts, let go of the key and accelerator. If the
vehicle starts briey but then stops again, do the
same thing, but this time keep the pedal down
for ve or six seconds. This clears the extra
gasoline from the engine.
Notice:Your engine is designed to work with the
electronics in your vehicle. If you add electrical
parts or accessories, you could change the way the
engine operates. Before adding electrical equipment,
check with your dealer. If you do not, your engine
might not perform properly.Adjustable Throttle and Brake Pedal
If your vehicle has this feature, you can change the
position of the throttle and brake pedals. This feature is
designed for shorter drivers, since the pedals cannot
move farther away from the standard position, but can
move closer for better pedal reach. This feature can
be programmed to work with the memory function
(if equipped) on your vehicle. SeeMemory Seat
on page 2-53.
The vehicle must be in PARK (P) for this feature to
operate.
The toggle switch used
to adjust the pedals is
located on the steering
column.
Press the switch towards you to move the pedals
closer. Press the switch away from you to move the
pedals away from you.
2-22

Engine Coolant Heater
Your vehicle may have this feature. In very cold
weather, 0°F (-18°C) or colder, the engine coolant
heater can help. You’ll get easier starting and better
fuel economy during engine warm-up. Usually, the
coolant heater should be plugged in a minimum of
four hours prior to starting your vehicle. At temperatures
above 32°F (0°C), use of the coolant heater is not
required.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located on the driver’s side of the
engine compartment, behind the battery.
3. Plug it into a normal, grounded 110-Volt
AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you don’t, it could be
damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature,
the kind of oil you have, and some other things. Instead
of trying to list everything here, we ask that you
contact your dealer in the area where you’ll be parking
your vehicle. The dealer can give you the best advice
for that particular area.
2-23

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.
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 your parking brake and move the shift
lever to PARK (P). SeeShifting Into Park (P)
on page 2-31. If you are pulling a trailer, see
Towing a Trailer on page 4-55.
{CAUTION:
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 — not in NEUTRAL. SeeFour-Wheel
Drive on page 2-26. SeeShifting Into Park (P)
on page 2-31.
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. SeeShifting
Out of Park (P) on page 2-33.
2-24

REVERSE (R):Use this gear to back up.
Notice:Shifting to REVERSE (R) while your vehicle
is moving forward could damage the transmission.
The repairs would not be covered by your warranty.
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, seeIf
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
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. Do not
shift into a drive gear while your engine is
running at high speed.Notice:Shifting out of PARK (P) or NEUTRAL (N)
with the engine running at high speed may damage
the transmission. The repairs would not be covered
by your warranty. Be sure the engine is not running
at high speed when shifting your vehicle.
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).
2-25

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.
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
rst gear until the vehicle is going slowly enough.
Notice:Spinning the tires or holding the vehicle
in one place on a hill using only the accelerator
pedal may damage the transmission. If you
are stuck, do not spin the tires. When stopping on
a hill, use the brakes to hold the vehicle in place.Four-Wheel Drive
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.
You should use two-wheel drive high (2HI) for most
normal driving conditions.
Notice:Driving on pavement in four-wheel drive
for an extended period of time may cause premature
wear on your vehicle’s powertrain. Do not drive in
four-wheel drive on pavement for extended periods
of time.
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.
2-26

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 3-48for 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.
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).
2-28

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.
SeeFour-Wheel Drive on page 2-26. 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 4-55.To shift into PARK (P), do the following:
1. Hold the brake pedal down with your foot and set
the parking brake.
2. Move the shift lever
into PARK (P) like this:
3. Press the button in on the side of the lever.
4. Push the lever all the way toward the front of the
vehicle.
5. Turn the ignition key to LOCK.
6. 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.
2-31

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 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