2000 CHEVROLET EXPRESS cooling

2-16
Rear Doors
CAUTION:
It can be dangerous to drive with the rear door(s)
or rear swing
-out windows open because carbon
monoxide (CO) gas can come into your vehicle.
You can't see or smell CO. It can cause
unconsciousness and even death.
CAUTION: (Continued)
CAUTION: (Continued)
If you must drive with the rear door(s) or rear
swing
-out windows open or if electrical wiring or
other cable connections must pass through the
seal between the body and the rear door(s) or
rear swing
-out windows:

Make sure all other windows are shut.

Turn the fan on your heating or cooling
system to its highest speed with the setting
on VENT, HEAT or DEFOG. Additionally,
on vehicles with heating/air conditioning
systems, MAX A/C or BI
-LEVEL A/C can
be used. That will force outside air into
your vehicle. See ªComfort Controlsº in
the Index.

If you have air outlets on or under the
instrument panel, open them all the way.
See ªEngine Exhaustº in the Index.

2-65 Malfunction Indicator Lamp (Service
Engine Soon Light) (Check Engine Light)
(8.1L Gasoline Engine -- Except California)
United States Canada
If this light comes on or flashes while you are driving,
two things may happen.
First, you won't notice any difference in engine
performance, but your tail pipe emissions may increase.
Second, your engine may not run properly or may stall
without warning. If either of these things happen, drive
or tow your vehicle to your dealer for service.This light should come on when the ignition is on, but
the engine is not running, as a check to show you it is
working. If it does not come on at all, have it repaired.
NOTICE:
If you keep driving your vehicle with this light
on, after a while, your emission controls may not
work as well, your fuel economy may not be as
good and your engine may not run as smoothly.
This could lead to costly repairs that may not be
covered by your warranty.
Reduced Engine Power
The REDUCED ENGINE
POWER light will come
on when the cooling system
temperature gets too hot
and the engine further
enters the engine coolant
protection mode.
See ªEngine Overheatingº in the Index for
further information.

3-2
Comfort Controls
This section tells you how to make your air system work
for you.
With these systems, you can control the heating, cooling
and ventilation in your vehicle.
System Controls
If your vehicle does not have air conditioning, your
controls will look like this.Fan Knob
The knob on the left side of the system control panel
regulates the fan speed. The knob has four speed
positions. To increase airflow, turn the knob toward HI.
To decrease airflow, turn it toward LO. To turn the fan
off, turn the mode knob on the far right to OFF.
Temperature Knob
The middle knob on the control panel regulates the
temperature of the air flowing into the passenger area of
your vehicle. This knob will allow you to adjust the
relative air temperature independently of the function
knob setting. Turn the knob toward the red area for
warmer air. Turn the knob toward the blue area for
cooler air.

3-4
Fan Knob
The knob on the left side of the control panel regulates
the fan speed. The knob has four speed positions. To
increase airflow, turn the knob toward HI. To decrease
airflow, turn it toward LO. To turn the fan off, turn the
mode knob on the far right to OFF.
Temperature Knob
The middle knob on the control panel lets you select
the temperature of the air flowing into the passenger
compartment of your vehicle. This knob will allow you
to adjust the air temperature independently of the
function knob setting. Turn the knob toward the red
area for warmer air. Turn the knob toward the blue
area for cooler air.
Mode Knob
The right knob on the control panel changes the
heater/air conditioning setting.
MAX A/C (Maximum Air Conditioning): Turn the
right knob to MAX A/C for maximum cooling. This
setting puts the system in the recirculation mode and
helps to maximize your air conditioner's performance
and your vehicle's fuel economy. This setting also coolsthe air the fastest. After the vehicle's interior reaches a
comfortable temperature, turn the knob clockwise to
place the air conditioning system in the A/C mode.
A/C (Air Conditioning): This setting is used for normal
cooling on hot days. It cools outside air and directs it
through the instrument panel outlets.
(Bi-Level Air Conditioning): This setting divides
airflow between the floor vents and instrument panel
vents. The air conditioning compressor will cycle
continuously in this setting as long as the outside air
temperature is warm enough to activate the compressor.
(Vent): This setting directs air through the
instrument panel vents.
(Floor): This setting directs air through the
floor vents.
(Floor/Defrost): This setting divides airflow
between the floor vents and the windshield. In the
blended position, the air conditioning compressor is
automatically activated to dehumidify the air.
(Defrost): This setting directs air through the
windshield defroster vents. It is useful when you have
fog or ice on the windshield.

3-9 Ventilation System
For mild outside temperatures when little heating or cooling
is needed, use vent to direct outside air through your vehicle.
Air will flow through the instrument panel vents.
Your vehicle's flow
-through ventilation system supplies
outside air to the inside of your vehicle when it is
moving. With the side windows closed, air will flow into
the front air inlet grilles at the base of the windshield,
through the vehicle and out of the rear air exhaust valve.
Outside air will also enter the vehicle when the heater or
the air conditioning is running.
Your vehicle has air vents near the center and on the
sides of the instrument panel that allow you to adjust the
direction and the amount of airflow inside the vehicle.
Move the thumbwheel on the vent up or down to direct
airflow to your preference. Increase or reduce the
amount of airflow by opening and closing the louvers.
The vents turn to direct the airflow from side to side.
When you close a vent, it will increase the flow of air
coming out of any vents that are open.
If you have rear heating or rear air conditioning, you
will have adjustable vents in the rear of the vehicle to
help direct the airflow. The rear air conditioning vents
are located in the headliner at the rear of the vehicle.
The rear heating vents are located next to the second
and third seat on the driver's side of the vehicle, near
the floor. You can move the vents to direct the flow of
air, or close the vents altogether. When you close a vent,
it will increase the flow of air coming out of any vents
that are open.

4-23
If you drive regularly in steep country, or if you're
planning to visit there, here are some tips that can make
your trips safer and more enjoyable.

Keep your vehicle in good shape. Check all fluid
levels and also the brakes, tires, cooling system and
transmission. These parts can work hard on
mountain roads.

Know how to go down hills. The most important
thing to know is this: let your engine do some of the
slowing down. Shift to a lower gear when you go
down a steep or long hill.
CAUTION:
If you don't shift down, your brakes could get
so hot that they wouldn't work well. You would
then have poor braking or even none going
down a hill. You could crash. Shift down to let
your engine assist your brakes on a steep
downhill slope.
CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. Your brakes will have to
do all the work of slowing down. They could get so
hot that they wouldn't work well. You would then
have poor braking or even none going down a hill.
You could crash. Always have your engine running
and your vehicle in gear when you go downhill.

Know how to go uphill. You may want to shift down
to a lower gear. The lower gears help cool your engine
and transmission, and you can climb the hill better.

Stay in your own lane when driving on two
-lane
roads in hills or mountains. Don't swing wide or cut
across the center of the road. Drive at speeds that let
you stay in your own lane.

As you go over the top of a hill, be alert. There could be
something in your lane, like a stalled car or an accident.

You may see highway signs on mountains that warn of
special problems. Examples are long grades, passing or
no
-passing zones, a falling rocks area or winding
roads. Be alert to these and take appropriate action.

4-38 Driving with a Trailer
CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You can't see
or smell CO. It can cause unconsciousness or
death. See ªEngine Exhaustº in the Index.
To maximize your safety when towing a trailer:

Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.

Keep the rear
-most windows closed.

If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use
MAX A/C because it only recirculates the
air inside your vehicle. See ªComfort
Controlsº in the Index.
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you'll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the
trailer. And always keep in mind that the vehicle you
are driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving
and then apply the trailer brake controller by hand to be
sure the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.

4-41 Parking on Hills
CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People can
be injured, and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet. Then turn your wheels into the curb
if facing downhill or into traffic if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your parking
brake and then shift to PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:

start your engine,

shift into a gear, and

release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't overfill),
engine oil, axle lubricant, belt, cooling system and brake
system. Each of these is covered in this manual, and the
Index will help you find them quickly. If you're trailering,
it's a good idea to review these sections before you start
your trip.
Check periodically to see that all hitch nuts and bolts
are tight.