2003 CHEVROLET C/K engine coolant

2-29 To Use the Engine Coolant Heater
1. Turn off the engine.
2. Find the plug
-in receptacle (either behind the front
bumper or in the component box).
3. Plug a heavy
-duty, three-prong extension cord
(rated for at least 15 amps) into the vehicle's plug
-in
receptacle first. Then plug the extension cord 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. Use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug
the cord.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature.
From 32
F to
-10
F (0
C to -23
C), keep the coolant
heater plugged in at least two hours. Below
-10
F
(
-23
C), keep the coolant heater plugged in for a
minimum of eight hours or overnight. It will not harm
either the coolant heater or the vehicle to leave the
coolant heater plugged in longer than the times stated.
Be sure to remove and store the cord before starting the
engine. See ªDiesel Fuel Requirements and Fuel
Systemº in the Index for information on what fuel to
use in cold weather.

2-84 Trailer Anti-Lock Brake System
Warning Light
If your vehicle is connected
to an anti
-lock brake system
equipped trailer, this light
should come on briefly, as
a check, when you turn on
the ignition.
When this light comes on and stays on, it means there is
something wrong in the trailer anti
-lock brake system.
Have the system repaired immediately.
If an anti
-lock brake system equipped trailer is not
connected, this light is not functional.
Engine Coolant Temperature Gage
United States Canada
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, your engine
coolant might have overheated and your engine may be
too hot. You should pull off the road, stop your vehicle
and turn off the engine as soon as possible.
See ªEngine Overheatingº in the Index. If you have a
Caterpillar

diesel engine, also see your Caterpillar

Operation & Maintenance Manual.

2-85 Low Coolant Warning Light
You have a low coolant
warning light. If this light
comes on, your system is
low on coolant and the
engine may overheat.
The warning light should come on briefly, as a check,
when you turn on the ignition.
When it comes on, you will also hear a warning tone at
several beats per second for 10 seconds. See ªEngine
Coolantº in the Index and have your vehicle serviced as
soon as you can.
This light may also come on if your vehicle is equipped
with the automatic engine shutdown system and engine
shutdown has begun. See ªEngine Automatic
Shutdownº in the Index.
Wait to Start Indicator (If Equipped)
This light in the center of
the instrument panel will
come on when the intake
heater is on and the ignition
key is in RUN.
Wait until the indicator light turn off before turning the
ignition key to START. See ªEngine Startingº in your
Caterpillar

Operation & Maintenance Manual for more
information.

2-92 Daytime Running Lamps (DRL)
Indicator Light
This light is located on the
instrument panel cluster. It
goes on whenever the
Daytime Running Lamps
are on.
See ªDaytime Running Lampsº in the Index.
When it begins to get dark, the DRL indicator light is a
reminder to turn on your headlamps.
Low Washer Fluid Warning Light
This light will come on
when your vehicle is low on
windshield washer fluid.
For more information, see ªWindshield Washer Fluidº in
the Index.
Check Gages Indicator Light
This light will come on as
you're starting the engine,
just as a check.
If it ever comes on and stays on while you are driving,
however, it means that either your engine coolant
temperature gage or your engine oil pressure gage may
be showing a reading in the warning zone.
When the check gages light comes on, you will also hear
a warning tone. The tone and the light will stay activated
until the problem is corrected.
This light may also come on if your vehicle is equipped
with the optional automatic engine shutdown system and
engine shutdown has begun. See ªEngine Automatic
Shutdownº in the Index.

3-4
(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.
(Defog): This setting divides airflow between the
floor vents and windshield vents.
(Defrost): This setting directs air through the
windshield vents. This setting is used to remove fog or
ice from the windshield.
Air Conditioning (If Equipped)
Before using the air conditioning, open the windows to
clear the vehicle of hot air. This reduces the time it takes
for your vehicle to cool down. Then keep your windows
closed for the air conditioner to work at its best.You can use maximum air conditioning with the
temperature knob in the blue area when it's really hot
outside and you need to cool the inside air quickly.
Maximum air conditioning lets in only a little air from
the outside.
If you first use maximum air conditioning, you can then
use regular air conditioning with the temperature knob
in the blue area, as soon as the vehicle has cooled down,
so outside air will be going through your vehicle.
While in maximum air conditioning, regular air
conditioning, bi
-level air conditioning, defog or defrost
mode, you may notice a slight increase or decrease in
engine speed, due to compressor operation. This is
normal because the system is designed to cycle the
compressor on and off to maintain the desired
temperature.
Heating
On cold days, use floor with the temperature knob in the
red area. Outside air will be brought in, heated and
distributed through the floor vents. The heater works
best if you keep your windows closed while using it.
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.

5-17
6. Turn the stud nut
clockwise several turns
to release the brakes.
Follow the same
procedure to release the
other brake.
7. At the repair facility, apply air pressure of at least
70 psi (480 kPa) to the brake chambers, either from
an external air supply or the vehicle's air system.
8. Turn the stud nut counterclockwise several turns.
Remove the stud from the chamber.
9. Replace the stud and washer and tighten the nut
into the side of the chamber.
10. Replace the rubber cap.Engine Overheating
You will find a coolant temperature warning gage on
your vehicle's instrument panel, as well as a low coolant
warning light. Your vehicle also has a check gages
warning light on the instrument panel.

5-18 If Steam Is Coming From Your Engine
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.

5-19 If No Steam Is Coming From Your Engine
An overheat warning, along with a low coolant light,
can indicate a serious problem. See ªLow Coolant
Lightº in the Index.
If you get an engine overheat warning with no low
coolant light, 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.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in neutral while
stopped. If it is safe to do so, pull off the road, shift
to park or neutral and let the engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If climbing a hill, downshift to raise engine and
fan speeds.If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn't come back on, you can drive
normally.
If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.
If there's still no sign of steam, you can push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you're parked. If you still have the warning, turn off
the engine and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.