1999 GMC ENVOY heater

yellowblue
1-4
3. To program your keyless entry transmitter, press the
UNLOCK button within five seconds of
programming the memory button. You will hear a
chime to confirm programming of the transmitter.
When your vehicle is in PARK (P), push and release the
numbered memory button you just stored. The seat will
move to the set position. You will hear one chime.
Repeat Steps 1 and 2 to readjust the seat. The transmitter
need not be reprogrammed unless it needs to correspond
to the other numbered memory button.
If there is a third driver, use the seat adjuster switch to
adjust the seat.
Pressing any of the seat adjuster switches, the SET
button or pressing the desired memory button twice will
cause the seat to stop moving. If you push the numbered
button to adjust the seat and start the vehicle while the
seat is still adjusting, adjustment will pause while the
ignition is in START. Adjustment will resume after the
ignition is in RUN.Heated Front Seats
This control is located on
the side of the seat. This
feature will quickly heat the
lower cushion and lower
back of the driver and
front passenger seats for
added comfort.
Press the lower part of the switch to turn the heater on
low. Press the upper part of the switch to turn the heater
on high. Put the switch in the center position to turn the
heater off.
The passenger's safety belt must be engaged for the
heated seat feature to work on the passenger's seat.
ProCarManuals.com

2-
yellowblue
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 Keys
2
-4 Door Locks
2
-6 Keyless Entry System
2
-9 Liftgate/Liftglass
2
-10 Theft
2
-11 Content Theft-Deterrent
2
-12 Passlock

2-13 New Vehicle ªBreak-Inº
2
-14 Ignition Positions
2
-16 Starting Your Engine
2
-17 Engine Coolant Heater (If Equipped)
2
-18 Automatic Transmission Operation
2
-21 Tow/Haul Selector Switch
2
-21 Four-Wheel Drive
2
-25 Parking Brake
2
-26 Shifting Into PARK (P)
2
-28 Shifting Out of PARK (P)
2
-29 Parking Over Things That Burn2
-30 Engine Exhaust
2
-30 Running Your Engine While You're Parked
2
-31 Locking Rear Axle
2
-31 Windows
2
-33 Tilt Wheel
2
-33 Turn Signal/Multifunction Lever
2
-40 Exterior Lamps
2
-42 Interior Lamps
2
-44 Mirrors
2
-46 Storage Compartments
2
-54 Ashtrays and Cigarette Lighter
2
-55 Sun Visors
2
-55 Accessory Power Outlets
2
-58 Sunroof (If Equipped)
2
-58 Universal Transmitter
2
-62 Instrument Panel
2
-64 Instrument Panel Cluster
2
-66 Warning Lights, Gages and Indicators
ProCarManuals.com

yellowblue
2-17
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 don't,
your engine might not perform properly.
If you ever have to have your vehicle towed, see
the part of this manual that tells how to do it
without damaging your vehicle. See ªTowing
Your Vehicleº in the Index.
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.
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.
ProCarManuals.com

yellowblue
2-18
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.
Automatic Transmission Operation
There are several different positions for your shift lever.
PARK (P): This locks your rear wheels. It's the best
position to use when you start your 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 firmly set. Your vehicle can roll.
Don't 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 won't move, even when you're on fairly
level ground, always set your parking brake and
move the shift lever to PARK (P).
See ªShifting Into PARK (P)º in the Index. If
you're pulling a trailer, see ªTowing a Trailerº in
the Index.
ProCarManuals.com

yellowblue
3-3
Mode Knob - Automatic Operation
The right knob on the control panel allows you to
choose the direction of air delivery. When the system is
set for automatic operation, sensors will control the air
delivery mode. Air will come primarily from the floor or
instrument panel outlets, with some air directed to the
windshield to prevent fogging.
When the system is in AUTO mode, the air conditioning
light will turn on, and the recirculation and outside air
lights turn off. With the system in full auto control (both
the fan and mode knobs in AUTO), you still have the
ability to override any function. However, continually
overriding the outside air or the A/C compressor will limit
the ability of the system to cool the vehicle quickly.
If you push a button for a function which is not
available, the light next to that button will flash three
times to alert you that it's not available.
To find your comfort zone, start with the 74
F (23
C)
setting and allow about 20 minutes for the system to
adjust the temperature if necessary.
With the automatic setting, the air conditioning compressor
automatically cycles when needed to cool the air. In cold
weather, when the system senses the need for heat, the
airflow will be directed out the floor outlets. As the
interior temperature approaches the desired setting, theblower speed will decrease. To maintain interior comfort,
the airflow will adjust between the instrument panel air
outlets and floor outlets. On bright sunny days in cool
weather, the airflow may come out of the air conditioning
and floor outlets (bi
-level mode) to maintain comfort and
prevent stuffiness.
To avoid blowing cold air in cold weather, the system will
delay turning on the fan until warm air is available. The
length of delay depends on the outside air temperature,
engine coolant temperature or the time since the engine
was last started. As the coolant warms up, the blower fan
speed will gradually increase and air will flow from the
heater outlets, with some airflow to the windshield to
prevent fogging under most normal conditions.
If your vehicle is sitting out on a warm day and you
have the fan set on AUTO, the air will first flow out of
the floor air outlets for a few seconds. That is normal.
This is to expel hot air from the air outlets. As the air is
cooled, the airflow will move through the air
conditioning outlets.
Be careful not to put anything over the solar sensor
located around the center of the instrument panel.
This sensor is used by the automatic system to
regulate temperature.
ProCarManuals.com

yellowblue
3-4
Mode Knob - Manual Operation
The right knob on the control panel allows you to
choose the direction of air delivery.
You can choose to set the climate control system
operations yourself, or let the system work for you by
placing the system in AUTO mode. See ªMode
Knob
- Automatic Operationº earlier in this section.
PANEL: This setting directs most of the air
through the instrument panel outlets and a small amount
through the floor outlets.
BI-LEVEL: Air is delivered through the heater
floor outlets as well as the instrument panel outlets.
HEATER: This setting directs most of the
warmed air through the heater floor outlets and some air
through the windshield defroster outlets.
BLEND: Airflow is divided equally between the
heater floor outlet and the windshield defroster outlets.
The air conditioning compressor may run to dehumidify
the air to prevent window fogging.
DEFROST: This setting directs most air through
the windshield defroster outlets and some through the
heater outlets. The air conditioning compressor may run
to dehumidify the air to prevent window fogging.
OUTSIDE AIR: Press this button to force the
system to use outside air. Press it again to close off the
outside air.
Pressing the OUTSIDE AIR button will cancel the
RECIRCULATION button.
RECIRCULATION: Press this button to limit the
amount of fresh air entering your vehicle. This is helpful
when you are trying to limit odors entering your vehicle. In
the AUTO mode, the system will use recirculation as
necessary to cool the air. Pressing the recirculation button
will change the operation to a manual mode and the air will
recirculate non
-stop.
RECIRCULATION may be selected with the fan control
in OFF to limit odors, outside air and dust from entering
your vehicle.
Pressing the RECIRCULATION button will cancel the
OUTSIDE AIR button.
A/C: Press this button to turn the air conditioning
on and off. The system will cool and dehumidify the air
inside the vehicle when the A/C light is on.
Air conditioning will be automatically disabled when
the outside temperature drops below a level which air
conditioning is ineffective.
Remember that in order for the automatic system to perform
well, it needs A/C to provide cooling performance.
ProCarManuals.com

yellowblue
3-5 Air Conditioning
On hot days, open the windows long enough to let hot
inside air escape. This reduces the time it takes for your
vehicle to cool down. Then keep your windows closed
for the air conditioner to work its best.
For quick cool
-down on very hot days, the A/C button
should be enabled and the OUTSIDE AIR button should
not be active.
On cool but sunny days, use BI
-LEVEL A/C to deliver
warm air to the floor and cooler air to the instrument
panel outlets.
When the air conditioner is on, you may sometimes
notice slight changes in your vehicle's engine speed and
power. This is normal because the system is designed to
cycle the compressor on and off to keep the
desired temperature.
Heating
The heater works best if you keep your windows closed
while using it. On cold days, use HEATER with the
temperature knob turned toward the red area. BLEND is
useful in cool weather when you have fog or ice on the
windshield or side windows.
If you use the optional engine coolant heater before
starting your engine, your heating system will produce
warmer air faster to heat the passenger compartment in
cold weather. See ªEngine Coolant Heaterº in the Index.
Defogging and Defrosting
On cool, humid days, use BLEND to keep the
windshield and side windows clear.
Use DEFROST to remove fog or ice from the
windshield quickly in extreme humid or cold conditions.
Turn the temperature knob toward the red area and
move the fan control toward the red area.
ProCarManuals.com

yellowblue
3-7 Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use PANEL with the OUTSIDE AIR
button enabled to direct outside air through your vehicle.
Airflow is through the instrument panel outlets.
Your vehicle's ventilation system supplies outside air to
the inside of your vehicle when it is moving. When the
vehicle is not moving, you can get outside air to flow
through by selecting any mode and any fan speed.
You will find air outlets in the center and on the sides of
your instrument panel.You can direct the airflow side
-to-side by rotating the
thumbwheel located in the center of the vent. The vent
can be tilted up and down also. To control the amount of
airflow through the outlets, rotate the thumbwheel
below the vent.
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 far better, reducing the
chance of fogging the inside of your windows.

When you enter a vehicle in cold weather, move the
fan control to the right to the highest setting for a
few moments before driving off. This helps clear the
intake ducts of snow and moisture, and reduces the
chance of fogging the inside of your windows.

Keep the air path under the front seats clear of
objects. This helps air to circulate throughout
your vehicle.
ProCarManuals.com