2002 CHEVROLET TRAIL BLAZER cooling

5-15 How to Add Coolant to the Radiator
1. You can remove the radiator pressure cap when
the cooling system, including the radiator pressure
cap and upper radiator hose, is no longer hot.
Turn the pressure cap slowly counterclockwise
about one full turn.
If you hear a hiss, wait for that to stop.
A hiss means there is still some pressure left.
2. Then keep turning the pressure cap. Remove the
pressure cap.

5-17
6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
filler neck may be lower. If the level is lower, add
more of the proper DEX
-COOL
coolant mixture
through the filler neck until the level reaches the
base of the filler neck.
8. Then replace the pressure cap. At any time during
this procedure if coolant begins to flow out of the
filler neck, reinstall the pressure cap. Be sure the
pressure cap is hand
-tight.
Engine Fan Noise
This vehicle has a clutched engine cooling fan. When the
clutch is engaged, the fan spins faster to provide more air
to cool the engine. In most everyday driving conditions
the clutch is not engaged. This improves fuel economy
and reduces fan noise. Under heavy vehicle loading,
trailer towing, and/or high outside temperatures, the fan
speed increases when the clutch engages. So you may
hear an increase in fan noise. This is normal and should
not be mistaken as the transmission slipping or making
extra shifts. It is merely the cooling system functioning
properly. The fan will slow down when additional
cooling is not required and the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.

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 lights and 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.

6-25 What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL
coolant which won't damage
aluminum parts. If you use this coolant mixture, you
don't need to add anything else.
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:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the engine, radiator, heater core
and other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
NOTICE:
If you use the proper coolant, you don't have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.

6-27
Add coolant mixture at the recovery tank, but be careful
not to spill it.
CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
Occasionally check the coolant level in the radiator.
For information on how to add coolant to the radiator,
see ªCooling Systemº in the Index.
Radiator Pressure Cap
NOTICE:
Your radiator cap is a 15 psi (105 kPa)
pressure
-type cap and must be tightly installed to
prevent coolant loss and possible engine damage
from overheating.
See ªEngine Compartment Overviewº in the Index for
information on location.

6-45
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted the
same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new GM original
equipment parts. This way, you will be sure to have the
right wheel, wheel bolts and wheel nuts for your vehicle.
CAUTION:
Using the wrong replacement wheels, wheel bolts
or wheel nuts on your vehicle can be dangerous.
It could affect the braking and handling of your
vehicle, make your tires lose air and make you
lose control. You could have a collision in which
you or others could be injured. Always use
the correct wheel, wheel bolts and wheel nuts
for replacement.
NOTICE:
The wrong wheel can also cause problems with
bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper
height, vehicle ground clearance and tire or tire
chain clearance to the body and chassis.
See ªChanging a Flat Tireº in the Index for
more information.
Used Replacement Wheels
CAUTION:
Putting a used wheel on your vehicle is dangerous.
You can't know how it's been used or how far it's
been driven. It could fail suddenly and cause an
accident. If you have to replace a wheel, use a new
GM original equipment wheel.

6-59
Mini Fuses Usage
1 ECAS
2 Passenger's Side
High
-Beam Headlamp
3 Passenger's Side
Low
-Beam Headlamp
4 Back
-Up Trailer Lamps
5 Driver's Side
High
-Beam Headlamp
6 Driver's Side
Low
-Beam Headlamp
7 WASH
8ATC
9 Windshield Wipers
10 Powertrain Control Module B
11 Fog Lamps
12 ST/LP
13 Cigarette Lighter
14 COILS
15 RIDE
16 TBD
-- Ignition 1Mini Fuses Usage
17 Crank
18 Air Bag
19 ELEK Brake
20 Cooling Fan
21 Horn
22 Ignition E
23 ETC
24 Instrument Panel Cluster, Driver
Information Center
25 Automatic Shift Lock
Control System
26 ENG 1
27 Back
-Up
28 Powertrain Control Module 1
29 Oxygen Sensor
30 Air Conditioning
31 TBC
50 Passenger's Side Trailer TRN
51 Driver's Side Trailer TRN
52 Hazard Flashers

6-60
J-Case Fuses Usage
32 Trailer
33 Anti
-Lock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Ignition B
Micro Relays Usage
37 Blank
38 Rear Window Washer
39 Fog Lamps
40 Horn
41 Fuel Pump
42 Windshield Wipers/Washer
43 High
-Beam Headlamp
44 Air Conditioning
Solid
State RelaysUsage
45 Cooling Fan
46 HDMMini Relay Usage
47 Starter
Miscellaneous Usage
48 Instrument Panel Battery
49 Fuse Puller
Rear Underseat Fuse Block
The rear underseat fuse block is located under the rear
seat on the driver's side of the vehicle.