2004 GMC ENVOY trailer

Passlock®
Your vehicle is equipped with the
Passlock®theft-deterrent system.
Passlock
®is a passive theft-deterrent system that
enables fuel if the ignition lock cylinder is turned with a
valid key. If a correct key is not used or the ignition
lock cylinder is tampered with, the fuel system is
disabled and the vehicle will not start.
During normal operation, the security light will turn off
approximately ve seconds after the key is turned
to RUN.
If the engine stalls and the security light ashes, wait
about 10 minutes until the light stops ashing before
trying to restart the engine. Remember to release
the key from START as soon as the engine starts.
If the engine does not start after three tries, the vehicle
needs service.
If the engine is running and the security light comes on,
you will be able to restart the engine if you turn the engine
off. However, your Passlock
®system is not working
properly and must be serviced by your dealer. Your
vehicle is not protected by Passlock
®at this time. You
may also want to check the fuse. SeeFuses and Circuit
Breakers on page 5-101. See your dealer for service.
In an emergency, call the GM Roadside Assistance
Center. SeeRoadside Assistance Program on page 7-6.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
“break-in.” But it will perform better in the long run
if you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less for
the rst 500 miles (805 km).
Do not drive at any one speed — fast or
slow — for the rst 500 miles (805 km). Do not
make full-throttle starts.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time your new
brake linings are not yet broken in. Hard stops
with new linings can mean premature wear
and earlier replacement. Follow this breaking-in
guideline every time you get new brake
linings.
Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-55for more information.
2-19

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,
see If You Are Stuck: In Sand, Mud, Ice or Snow on
page 4-42.
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 racing may damage the
transmission. The repairs would not be covered by
your warranty. Be sure the engine is not racing
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.
2-25

Parking Brake
To set the parking brake, hold the regular brake pedal
down with your foot and pull up on the parking brake
lever. If the ignition is on, the brake system warning light
will come on.
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.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 4-55. That section
shows what to do rst to keep the trailer from moving.
2-30

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:
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.
2-31

{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
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 — 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.
Follow the proper steps to be sure your vehicle will not
move. SeeShifting Into Park (P) on page 2-31.
If you are pulling a trailer, seeTowing a Trailer on
page 4-55.
2-35

Turn and Lane Change Signals
The turn signal has two upward (for right) and two
downward (for left) positions. These positions allow you
to signal a turn or a lane change.
To signal a turn, move the lever all the way up or down.
When the turn is nished, the lever will return
automatically.
An arrow on the instrument
panel cluster will ash in
the direction of the
turn or lane change.
To signal a lane change, just raise or lower the lever
until the arrow starts to ash. Hold it there until you
complete your lane change. The lever will return by itself
when you release it. The bottom of the outside
rearview mirrors may also be equipped with lane change
indicators.As you signal a turn or a lane change, if the arrows
ash more quickly than normal, a signal bulb may
be burned out and other drivers won’t see your turn
signal.
If a bulb is burned out, replace it to help avoid an
accident. If the arrows don’t go on at all when you signal
a turn, check the fuse. SeeFuses and Circuit Breakers
on page 5-101and check for burned-out bulbs.
If you have a trailer towing option with added wiring for
the trailer lamps, a different turn signal asher is
used. With this asher installed, the signal indicator will
ash even if a turn signal bulb is burned out. Check
the front and rear turn signal lamps regularly to make
sure they are working.
Turn Signal On Chime
If your turn signal is left on for more than 3/4 of a mile
(1.2 km), a chime will sound at each ash of the
turn signal. To turn off the chime, move the turn signal
lever to the off position.
3-8

Notice:Modications made to the engine,
transmission, exhaust, intake or fuel system of your
vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is
not running. If the light does not come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed.
Avoiding hard accelerations.
Avoiding steep uphill grades.
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stops ashing and remains on steady, see “If
the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle.Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see “If
the Light Is On Steady” following. If the light is still
ashing, follow the previous steps, and see your dealer
for service as soon as possible.
3-41