coolant temperature CHEVROLET C3500 HD 2002 4.G Owners Manual

2-16
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 engine coolant heater electrical cord is located
on the driver's side of the engine compartment, near
the power steering reservoir.
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.

2-17
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.
If your vehicle is equipped with an automatic
transmission, it features an electronic shift position
indicator within the instrument panel cluster. This
display must be powered any time the shift lever is
capable of being moved out of PARK (P). This means
that if your key is in OFF, rather than LOCK, there will
be a small current drain on your battery which could
discharge your battery over a period of time. If you have
to leave your key in the ignition in OFF for an extended
period, it is recommended that you disconnect the
battery cable from the battery to prevent discharging
your battery.

2-56 Engine Coolant Temperature Gage
This gage shows the engine
coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210
F (100
C) or less. If you are pulling a
load or going up hills, it is normal for the temperature to
fluctuate and approach the 260
F (125
C) mark. If the
gage reaches the 260
F (125
C) mark, it indicates that
the cooling system is working beyond its capacity.
See ªEngine Overheatingº in the Index.
Malfunction Indicator Lamp (Service
Engine Soon Light in the United States
or Check Engine Light in Canada)
(Gasoline Engine)
United States Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition and emission
control systems.

2-60 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.
Oil Pressure Gage
United States Canada
The oil pressure gage shows the engine oil pressure in
psi (pounds per square inch) when the engine is running.
Canadian vehicles indicate pressure in kPa (kilopascals).

2-62 Up Shift Light (If Equipped)
This light is used on models
with manual transmissions.
The SHIFT indicator light will help you get the best fuel
economy. See ªShift Lightº or ªShift Speedsº in this
section for more information.
Daytime Running Lamps Indicator Light
This light goes on whenever
the DRL are on.
When it begins to get dark, the DRL indicator light
comes on as a reminder to turn on your headlamps.
Check Gages Light
This light will come on
briefly when you are
starting the engine.
If the light comes on and stays on while you are driving,
it could indicate a problem with your vehicle. It could be
a problem with your oil pressure, coolant temperature,
or some other problem. Check your various gages to see
if they are in the warning zones. If they are, have your
vehicle serviced right away.

3-4 Air Conditioning
On hot days, open the windows long enough to let hot
air inside 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.
A/C (Air Conditioning): Press this button to turn the
air conditioning compressor 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 at which
air conditioning is ineffective.
With the A/C on, turn the temperature knob to MAX
for maximum cooling. This setting also puts the system
in the recirculation mode and helps to maximize your
air conditioner's performance and your vehicle's
fuel economy.
(Recirculation): Pressing the recirculation
button limits the amount of outside dust and odors
entering your vehicle. This button will be automatically
disabled anytime the mode knob is turned to blend or
defrost mode. (The recirculation indicator light will
come on even though the recirculation button is not
selected). This setting also cools the air the fastest.After the vehicle's interior reaches a comfortable
temperature, turn the temperature knob clockwise, to
place the air conditioning system in the normal mode.
Heating
The heater works best if you keep your windows closed
while using it. On cold days, use the floor or bi
-level
setting with the temperature knob in the red area.
If you use the engine coolant heater before starting your
engine in cold weather, 20
F (
-8
C) or lower, your
heating system will produce warmer air faster, to heat
the passenger compartment in cold weather.
The use of an engine coolant heater also reduces the
time it takes for the engine to reach normal operating
temperature, and shortens the time it takes the heater to
reach full output. For more information, 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 in extremely humid or cold
conditions. Use defrost with the temperature knob
toward the red area and the fan control toward HI.

4-36 Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much
that they would get hot and no longer work well.
If you have an automatic transmission, you can tow in
AUTOMATIC OVERDRIVE (
). You may want to
shift the transmission to THIRD (3) or, if necessary, a
lower gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
If you have a manual transmission and you are towing a
trailer, it's better not to use FIFTH (5) gear. Just drive
in FOURTH (4) gear (or, as you need to, a lower gear).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If you
turn your engine off immediately after towing at high
altitude on steep uphill grades, your vehicle may show
signs similar to engine overheating. To avoid this,
let the engine run while parked (preferably on level
ground) with the automatic transmission in PARK (P)
(or the manual transmission out of gear and the
parking brake applied) for a few minutes before
turning the engine off. If you do get the overheat
warning, see ªEngine Overheatingº in the Index.
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 for an automatic transmission,
or into gear for a manual transmission.
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 shift into PARK (P) for an
automatic transmission, or REVERSE (R) for a
manual transmission.
5. Release the regular brakes.

5-9
To disconnect the jumper cables from both vehicles,
do the following:
1. Disconnect the black negative (
-) cable from the
vehicle that has the dead battery.
2. Disconnect the black negative (
-) cable from the
vehicle with the good battery.
3. Disconnect the red positive (+) cable from the
vehicle with the good battery.
4. Disconnect the red positive (+) cable from the
other vehicle.
Towing Your Vehicle
Consult your dealer or a professional towing service
if you need to have your disabled vehicle towed.
See ªRoadside Assistanceº in the Index.
Engine Overheating
(Gasoline Engine)
You will find a coolant temperature gage on your
vehicle's instrument panel. See ªEngine Coolant
Temperature Gageº in the Index.
If your vehicle has a diesel engine, see ªEngine
Overheatingº in the Diesel Engine Supplement.

6-24
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, see ªEngine Overheatingº in
the Index.
A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning gages work as they should.
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.

6-29
Windshield Washer Fluid
What to Use
When you need windshield washer fluid, be sure to read
the manufacturer's instructions before use. If you will be
operating your vehicle in an area where the temperature
may fall below freezing, use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
Open the cap with the
washer symbol on it.
Add washer fluid until
the tank is full.
NOTICE:

When using concentrated washer fluid,
follow the manufacturer's instructions for
adding water.

Don't mix water with ready
-to-use washer
fluid. Water can cause the solution to freeze
and damage your washer fluid tank and
other parts of the washer system. Also,
water doesn't clean as well as washer fluid.

Fill your washer fluid tank only
three
-quarters full when it's very cold.
This allows for expansion if freezing
occurs, which could damage the tank if
it is completely full.

Don't use engine coolant (antifreeze) in
your windshield washer. It can damage
your washer system and paint.