2001 GMC ENVOY engine

2-36
Shifting to 2HI
Press and release the 2HI switch. This can be done at
any speed.
Shifting to 4LO
To shift to 4LO, the vehicle's engine must be running
and the vehicle must be stopped or moving less
than 3 mph (4.8 km/h) with the transmission in
NEUTRAL (N) or with the clutch pedal pressed
for vehicles with manual transmission. The preferred
method for shifting into 4LO is to have your vehicle
moving 1 or 2 mph (1.6 to 3.2 km/h). Press and
release the 4LO switch. You must wait for the4LO
indicator light to stop flashing and remain illuminated
before shifting your transmission into gear.
If the 4LO switch is pressed when your vehicle is in
gear and/or moving, the 4LO indicator light will flash
for 30 seconds and not complete the shift unless your
vehicle is moving less than 3 mph (4.8 km/h) and the
transmission is in NEUTRAL (N) or with the clutch
pedal pressed for vehicles with manual transmission.
After 30 seconds, the transfer case will return to the
setting last chosen.Shifting Out of 4LO
To shift from 4LO to 4HI, AUTO 4WD or 2HI, your
vehicle must be stopped or moving less than 3 mph
(4.8 km/h) with the transmission in NEUTRAL (N),
or with the clutch pedal pressed for vehicles with manual
transmission, 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). Press and release
the 4HI, AUTO 4WD or 2HI switch. You must wait for
the 4HI, AUTO 4WD or 2HI indicator light to stop
flashing and remain illuminated before shifting your
transmission into gear.
If the 4HI, AUTO 4WD or 2HI switch is pressed when
your vehicle is in gear and/or moving, the 4HI, AUTO
4WD or 2HI indicator light will flash for 30 seconds but
will not complete the shift unless your vehicle is moving
less than 3mph (4.8 km/h) with the transmission in
NEUTRAL (N) or with the clutch pedal pressed for
vehicles with manual transmission.
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2-39
Shifting Into PARK (P)
(Automatic Transmission Only)
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 firmly 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, 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 ªFour-Wheel
Drive (Automatic Transfer Case)º in the Index.
Always put the shift lever fully in PARK (P) with
the parking brake firmly set. If you're pulling a
trailer, see ªTowing a Trailerº in the Index.
Column Shift Lever
1. Hold the brake pedal down with your right foot and
set the parking brake.
2. Move the shift lever into PARK (P) like this:

Pull the lever toward you.
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2-42
Leaving Your Vehicle With the Engine
Running (Automatic Transmission Only)
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 firmly set. 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. 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 fire. 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 firmly 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 first pulling
it toward you (or pressing the button on a console shift
lever). If you can, it means that the shift lever wasn't
fully locked into PARK (P).
Torque Lock (Automatic Transmission)
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 find it difficult to pull the
shift lever out of PARK (P). This is called ªtorque lock.º
To prevent torque lock, set the parking brake and then
shift into PARK (P) properly before you leave the
driver's seat. To find out how, see ªShifting Into
PARK (P)º in the Index.
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).
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2-44
Parking Over Things That Burn
CAUTION:
Things that can burn could touch hot exhaust
parts under your vehicle and ignite. Don't 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 can't see or
smell. It can cause unconsciousness and death.
You might have exhaust coming in if:

Your 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 weren't done correctly.

Your vehicle or exhaust system had been
modified 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 fixed immediately.
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2-45
Running Your Engine While You're
Parked (Automatic Transmission)
It's 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
ªEngine Exhaust.º
Also, idling in a closed-in place can let deadly
carbon monoxide (CO) into your vehicle even if
the fan switch 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.
See ªBlizzardº in the Index.
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 firmly 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).
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. See ªFour-Wheel
Drive (Automatic Transfer Case)º in the Index.
Follow the proper steps to be sure your vehicle won't
move. See ªShifting Into PARK (P)º in the Index.
If you're pulling a trailer, see ªTowing a Trailerº in
the Index.
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2-78
The light will be red in the event of an OnStar system
malfunction. If this occurs press the OnStar button to
attempt to contact an advisor. If the connection is made,
the advisor will assist you with steps to take to make
sure that the system is functioning properly. If you
cannot contact the advisor, take your vehicle to your
dealership as soon as possible for assistance.
Safety and Security Services

Automatic Notification of Air Bag
Deployment
-- If an air bag deploys, a priority
emergency signal is automatically sent to the center.
An advisor will locate your vehicle's position, try to
contact you and assist you in the situation. If the
center is unable to contact you, an emergency service
provider will be contacted.

Stolen Vehicle Tracking
-- Call the center at
1
-888-4-ONSTAR (1-888-466-7827) to report your
vehicle stolen. The system can then locate and track
your vehicle and the advisor will be able to notify
the proper authorities.

Roadside Assistance with Location
-- For vehicle
breakdowns, press the OnStar button. An advisor
will contact the appropriate help.
Remote Diagnostics
-- If an instrument panel light
comes on, the center can perform a check of the
engine on
-board computer. An advisor can then
recommend what action needs to be taken.

OnStar MED
-NET -- Med-Net can store your
personal medical history and provide it to emergency
personnel if necessary.

Accident Assist
-- An advisor can provide
step
-by-step guidance following an accident.

Remote Door Unlock
-- To contact the center,
call 1
-888-4-ONSTAR. You will be required to
provide your security information. An advisor will
send a command to your vehicle to unlock itself.
The advisor can delay unlocking your vehicle.
Remote Door Unlock is disabled 48 hours after
the vehicle is parked to maintain the battery charge.

Vehicle Locator Service
-- To contact the center,
call 1
-888-4-ONSTAR. You will be required to
provide your security information. An advisor will
send a command to your vehicle to sound the horn
and/or flash the lamps.
In order to provide you with excellent service, calls with
the OnStar Center may be monitored or recorded.
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2-81
Full-Size Console
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference,
and (2) this device must accept any interference received,
including interference that may cause undesired operation.
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, including interference
that may cause undesired operation of the device.
Changes and modifications to this system by other than
an authorized service facility could void authorization to
use this equipment.
Programming the Transmitter
Do not use the HomeLink Transmitter with any garage
door opener that does not have the ªstop and reverseº
feature. This includes any garage door opener model
manufactured before April 1, 1982.
Be sure that people and objects are clear of the garage
door you are programming.
Your vehicle's engine should be turned off while
programming the transmitter. Follow these steps to
program up to three channels:
1. If you have previously programmed a transmitter
channel, proceed to Step 2. Otherwise, hold
down the two outside buttons on the HomeLink
Transmitter until the indicator light begins to flash
rapidly (after 20 seconds). Then release the buttons.
This procedure initializes the memory and erases any
previous settings for all three channels.
2. Decide which one of the three channels you want to
program. Hold the end of the hand
-held transmitter
about 1 to 3 inches (3 to 8 cm) away from the
surface of the HomeLink Transmitter so that you
can still see the indicator light.
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2-88
Speedometer and Odometer
Your speedometer lets you see your speed in both miles
per hour (mph) and kilometers per hour (km/h).
Your odometer shows how far your vehicle has been
driven, in either miles (used in the United States) or
kilometers (used in Canada).
The odometer mileage can be checked without the
vehicle running. Simply press the trip odometer button.
You may wonder what happens if your vehicle needs a
new odometer installed. If the new one can be set to
the mileage total of the old odometer, then it must be.
But if it can't, then it's set at zero, and a label must be
put on the driver's door to show the old mileage reading
when the new odometer was installed.
Trip Odometer
The trip odometer can tell you how far your vehicle has
been driven since you last set the trip odometer to zero.
To view the trip odometer, press the button near the
readout. To reset the trip odometer, hold the button
until it resets.
Tachometer (If Equipped)
The tachometer displays the engine speed in revolutions
per minute (rpm).
NOTICE:
On vehicles with a manual transmission, if you
operate the engine with the tachometer in the
shaded warning areas, your vehicle's engine or
other parts of your vehicle could be damaged.
Damage to your engine or vehicle caused by
operating the engine with the tachometer in
the shaded warning areas isn't covered by your
vehicle warranty. Don't operate the tachometer
in the shaded warning areas.
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