2002 GMC ENVOY heater

2-
2-1
Section 2 Features and Controls
Here you can learn about the many standard and optional features on your vehicle, and information on starting,
shifting and braking. Also explained are the instrument panel and the warning systems that tell you if everything is
working properly
-- and what to do if you have a problem.
2
-2 Windows
2
-4 Keys
2
-6 Door Locks
2
-10 Remote Keyless Entry System
2
-13 Liftgate/Liftglass
2
-14 Theft
2
-15 Content Theft-Deterrent (If Equipped)
2
-17 Passlock

2-18 New Vehicle ªBreak-Inº
2
-18 Ignition Positions
2
-20 Starting Your Engine
2
-22 Engine Coolant Heater (If Equipped)
2
-23 Automatic Transmission Operation
2
-26 Four-Wheel Drive (If Equipped)
2
-31 Parking Brake
2
-32 Shifting Into PARK (P)
2
-34 Shifting Out of PARK (P)
2
-35 Parking Over Things That Burn
2
-35 Engine Exhaust2
-36 Running Your Engine While You're Parked
2
-37 Locking Rear Axle
2
-37 Horn
2
-37 Tilt Wheel
2
-38 Turn Signal/Multifunction Lever
2
-46 Exterior Lamps
2
-49 Interior Lamps
2
-51 Mirrors
2
-58 Storage Compartments
2
-62 Ashtrays and Cigarette Lighter
2
-65 Accessory Power Outlets
2
-66 OnStar
System (If Equipped)
2
-68 Sunroof (Option)
2
-69 HomeLink
Transmitter
2
-72 Instrument Panel -- Your Information System
2
-74 Instrument Panel Cluster
2
-75 Warning Lights, Gages and Indicators
2
-91 Driver Information Center (DIC)
(If Equipped)

2-22
Engine Coolant Heater (If Equipped)
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 underhood fuse block.
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 fire. You could be seriously injured. Plug the
cord into a properly grounded three
-prong
11 0
-volt AC outlet. If the cord won't 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.

3-8
If your vehicle has the automatic system, in AUTO
mode the system will cool and dehumidify the air
inside the vehicle. Also while in AUTO mode, the
system will maximize its performance by using
recirculation as necessary.
On cool, but sunny days, with the manual system or
through manual operation of the automatic system,
use bi
-level to deliver warm air to the floor and cooler
air to the instrument panel outlets. To warm or cool
the air delivered, turn the temperature control to the
desired setting.
Heating
If you have the manual system, on cold days use floor
with the temperature lever in the red area. If you have
the automatic system, press AUTO and adjust the
temperature by turning the temperature knob clockwise
or counterclockwise. You may also adjust the automatic
system manually by pressing the MODE button and
selecting floor. Again, adjust the temperature by turning
the temperature knob clockwise or counterclockwise.
With either system, outside air will be heated and sent
through the floor outlets. The heater works best if you
keep the windows closed while using it.
Defogging and Defrosting
On cool, humid days, use defog to keep the windshield
and side windows clear. Use front defrost to remove fog
or ice from the windshield quickly in extremely humid
or cold conditions.
If your vehicle has the manual system, select defog and
adjust the fan speed to your comfort level. Turn the air
conditioning on to help dehumidify the air. Use front
defrost with the temperature toward the red area and the
fan control toward high.
If your vehicle has the automatic system and you select
FRONT defrost or defog from AUTO, the system will
control the fan speed. Adjust the temperature and fan
speed to your comfort level. After the windshield is
clear, adjust the temperature to your normal setting and
select the AUTO button and return to AUTO mode and
fan control.
For maximum front defrost performance under extreme
icing or frosting conditions, increase the temperature
setting to 90
F (32
C) and increase the fan speed
to high.

3-12
Ventilation Tips

Keep the hood and front air inlet free of ice, snow or
any other obstruction such as leaves. The heater and
defroster will work better, reducing the chance of
fogging your windows.

In cool damp weather, minimize your use of
recirculation to reduce the chance of fogging
your windows.

When you enter a vehicle with the standard system
in cold weather, select floor mode to supply air
through the floor outlets. Then turn the fan on high
for a few moments before driving away. This will
blow moist air from the intake outlets toward the
floor, not the windshield. It reduces the chance of
fogging your windows. If you have the electronic
system, the AUTO setting will do this for you.
Manual operation of the electronic system in the
floor mode will also supply air through the
floor outlets.

Keep the air path under the front seats clear of
objects. This helps air to circulate throughout
your vehicle.Comfort Control Steering Wheel Controls
(If Equipped)
If your vehicle has this
feature, you can control
certain comfort control
functions using the buttons
on your steering wheel.
(Fan): Press the up arrow to increase the fan speed
and the down arrow to decrease the fan speed.
(Temperature): Press the up arrow to increase the
temperature of the air flowing through the system and
the down arrow to decrease the temperature of the air
flowing through the system.

4-43

Put on extra clothing or wrap a blanket around you.
If you have no blankets or extra clothing, make body
insulators from newspapers, burlap bags, rags, floor
mats
-- anything you can wrap around yourself or
tuck under your clothing to keep warm.
You can run the engine to keep warm, but be careful.
CAUTION:
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside. CO could overcome you and kill
you. You can't see it or smell it, so you might not
know it is in your vehicle. Clear away snow from
around the base of your vehicle, especially any
that is blocking your exhaust pipe. And check
around again from time to time to be sure snow
doesn't collect there.
Open a window just a little on the side of the
vehicle that's away from the wind. This will help
keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little faster
than just idle. That is, push the accelerator slightly. This
uses less fuel for the heat that you get and it keeps the
battery charged. You will need a well
-charged battery to
restart the vehicle, and possibly for signaling later on
with your headlamps. Let the heater run for a while.

5-9
CAUTION:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Just turn it off and get everyone away
from the vehicle until it cools down. Wait until
there is no sign of steam or coolant before you
open the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop your engine if
it overheats, and get out of the vehicle until the
engine is cool.
NOTICE:
If your engine catches fire because you keep
driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not be
covered by your warranty.
If No Steam Is Coming From Your Engine
If you get an engine overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:

Climb a long hill on a hot day.

Stop after high
-speed driving.

Idle for long periods in traffic.

Tow a trailer. See ªDriving on Gradesº in the Index.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If your air conditioner is on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- DRIVE (D) or THIRD (3).

5-11
When the engine is
cold, the coolant
level should be at
least up to the FULL
COLD mark. If it isn't,
you may have a leak at
the pressure cap or in
the radiator hoses,
heater hoses, radiator,
water pump or
somewhere else in
the cooling system.
CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Don't touch them.
If you do, you can be burned.
Don't run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
If there seems to be no leak, start the engine again. See if
the engine cooling fan speed increases when idle speed is
doubled by pushing the accelerator pedal down. If it
doesn't, your vehicle needs service. Turn off the engine.
NOTICE:
Engine damage from running your engine
without coolant isn't covered by your warranty.
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL
(silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL
is not
covered by your new vehicle warranty.

5-12 How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at the FULL COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX
-COOL
engine
coolant at the coolant recovery tank. See ªEngine
Coolantº in the Index for more information.
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the proper
coolant mixture will. Your vehicle's coolant
warning system is set for the proper coolant
mixture. With plain water or the wrong mixture,
your engine could get too hot but you wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.
NOTICE:
In cold weather, water can freeze and crack the
engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.