
CO(H6DO)-7
Radiator Fan System
COOLING
2. Radiator Fan System
A: WIRING DIAGRAM
CO-02209
RADIATOR FANCONTROL UNIT
132
B136
ECM
16
F109
F106
7
B360
2918
F106
123
B7
E
SBF-6MAIN SBF
NO.2
NO.26
B143B:
F36E:
E6
3127456
F36E:B143
123456712131415161718
B:
8191192010
EM
SUB FAN MOTORMAIN FAN MOTOR
THROUGH JOINTCONNECTOR
MAIN FANRELAY 1
MAIN FUSEBOX (M/B)
IGNITIONSWITCH
F17F11112
M
12
F111
F17
12
F109
3412 8910 1112 13 14 15 16 17 18 19 20 21 22 23 24567
B136
16101112131415252430
9871718192028212223293231
123456
2726333435
B360
12345678910111213141516

CO(H6DO)-8
Radiator Fan System
COOLING
B: RADIATOR FAN CONTROL OUTPUT WAVEFORM
C: INSPECTION
DETECTING CONDITION:
•Engine coolant temperature is more than 95°C (203°F).
•A/C switch is turned OFF.
•Vehicle speed is below 19 km/h (12 MPH).
TROUBLE SYMPTOMS:
Radiator main fan and sub fan do not rotate under the above conditions.
(A) 5 V
Step Check Yes No
1CHECK MAIN FAN RELAY 1.
1) Turn the ignition switch to OFF.
2) Remove the main fan relay 1 from A/C relay
holder.
3) Measure the resistance of terminal in main
fan relay 1 switch.
Is the resistance more than 1
MΩ?
Go to step 2.Replace the main
fan relay 1.
2CHECK MAIN FAN RELAY 1.
1) Connect the battery to terminal of main fan
relay 1 coil.
2) Measure the resistance between terminals
of main fan relay 1 switch.
Is the resistance less than 1
Ω?
Go to step 3.Replace the main
fan relay 1.
3CHECK POWER SUPPLY FOR ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM.
3) Turn the ignition switch ON.
4) Measure the voltage between ECM termi-
nal and chassis ground.
Connector & terminal
(B136) No. 29 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 4.Repair the power
supply line.
CO-02117
(V)
0
(A)

CO(H6DO)-9
Radiator Fan System
COOLING
4CHECK POWER SUPPLY FOR RADIATOR
FAN CONTROL UNIT.
1) Turn the ignition switch to OFF.
2) Connect the connector to ECM.
3) Disconnect the connector from radiator fan
control unit.
4) Turn the ignition switch ON.
5) Measure the voltage between radiator fan
control unit terminal and chassis ground.
Connector & terminal
(F106) No. 3 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 5.Repair the power
supply line.
5CHECK HARNESS BETWEEN ECM AND RA-
DIATOR FAN CONTROL UNIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from the ECM.
3) Measure the resistance between radiator
fan control unit and ECM connector.
Connector & terminal
(B136) No. 18 — (F106) No. 2:
Is the resistance less than 1
Ω?
Go to step 6.Repair the open
circuit of harness
between ECM and
radiator fan con-
trol unit.
6CHECK RADIATOR FAN CONTROL UNIT
AND GROUND CIRCUIT.
1) Connect the connector to ECM and radiator
fan control unit.
2) Measure the resistance between radiator
fan control unit connector and chassis ground.
Connector & terminal
(F106) No. 1 — Chassis ground:
Is the resistance less than 5
Ω?
Go to step 7.Repair the open
circuit of harness
between radiator
fan control unit
connector and
chassis ground.
7CHECK MAIN FAN MOTOR.
1) Disconnect the connector from radiator fan
control unit.
2) Connect the battery positive (+) terminal to
terminal No. 1 of the main fan motor, and the
ground (–) terminal to terminal No. 2.
Does the main fan motor
rotate?
Go to step 8.Replace the main
fan motor.
8CHECK SUB FAN MOTOR.
1) Disconnect the connector from radiator fan
control unit.
2) Connect the battery positive (+) terminal to
terminal No. 1 of the sub fan motor, and the
ground (–) terminal to terminal No. 2.
Does the sub fan motor rotate? Go to step 9.Replace the sub
fan motor.
9CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector.
3) Turn the ignition switch ON.
4) Check the output waveform using oscillo-
scope.
Fa n S y st e m. >
Connector & terminal
(B134) No. 18 (+) — Chassis ground (–):
Is waveform being output? Replace the radia-
tor fan control unit.
Radiator Fan Con-
trol Unit.>
Replace the ECM.
Engine Control
Module (ECM).>
Step Check Yes No

CO(H6DO)-10
Engine Coolant
COOLING
3. Engine Coolant
A: REPLACEMENT
1. DRAINING OF ENGINE COOLANT
1) Lift-up the vehicle.
2) Remove the under cover.
3) Remove the drain plug to drain engine coolant
into container.
NOTE:
Remove the radiator cap so that engine coolant will
drain faster.
4) Install the drain plug.
2. FILLING OF ENGINE COOLANT
1) Pour cooling system conditioner through the fill-
er neck.
Cooling system protective agent:
COOLING SYSTEM CONDITIONER (Part No.
SOA345001)
2) Pour engine coolant into the radiator up to the
filler neck position.
Coolant level:
Refer to “SPECIFICATION” for the engine
coolant capacity.
NOTE:
The SUBARU Genuine Coolant containing anti-
freeze and anti-rust agents is especially made for
SUBARU engine, which has an aluminum crank-
case. Always use SUBARU Genuine Coolant,
since other coolant may cause corrosion.
3) Open the air bleeding valve on the heater hose
side.
4) If the engine coolant level drops, add engine
coolant into radiator up to the filler neck position.
5) When engine coolant has come out from the air
bleeding valve on the heater hose side, close the
valve.
6) Open the air bleeding valve on the radiator side.
7) If the engine coolant level drops, add engine
coolant into radiator up to the filler neck position.
8) When engine coolant has come out from the air
bleeding valve on the radiator side, close the valve.
9) Fill engine coolant into the reservoir tank up to
“FULL” level.
10) Close the radiator cap and start the engine.
Race 5 to 6 times at less than 3,000 rpm, then stop
the engine. (Complete this operation within 40 sec-
onds.)
CO-02192
(1) FULL
(2) LOW
CO-02213
CO-02196
(1)
(2)

CO(H6DO)-11
Engine Coolant
COOLING
11) Wait for one minute after the engine stops,
open the radiator cap. If the engine coolant level
drops, add engine coolant into radiator up to the fill-
er neck position.
12) Perform the procedures 10) and 11) again.
13) Attach the radiator cap and reservoir tank cap
properly.
14) Start the engine and operate the heater at max-
imum hot position and the blower speed setting to
“LO.”
15) Run the engine at 2,000 rpm or less until radia-
tor fan starts and stops.
NOTE:
•Be careful with the engine coolant temperature
gauge to prevent overheating.
•If the radiator hose becomes harden with the
pressure of engine coolant, air bleeding operation
seems to be almost completed.
16) Stop the engine and wait until the engine cool-
ant temperature lowers to 30°C (86°F).
17) Open the radiator cap. If the engine coolant lev-
el drops, add engine coolant into radiator up to the
filler neck position and reservoir tank to the “FULL”
level.
18) Attach the radiator cap and reservoir tank cap
properly.
19) Set the heater setting to maximum hot position
and the blower speed setting to “LO” and start the
engine. Perform racing at less than 3,000 rpm. If
the flowing sound is heard at this time, perform the
procedures from 15) again.
B: INSPECTION
1. RELATIONSHIP OF SUBARU COOLANT
CONCENTRATION AND FREEZING TEM-
PERATURE
The concentration and safe operating temperature
of SUBARU coolant is shown in the diagram. Mea-
suring the temperature and specific gravity of the
coolant will provide this information.
[Example]
If the coolant temperature is 25°C (77°F) and its
specific gravity is 1.054, the concentration is 35%
(point A), the safe operating temperature is –14°C
(7°F) (point B), and the freezing temperature is –
20°C (–4°F) (point C).
CO-02172
60%
(1.054)
1.000
1.010
1.020
1.030
1.040
1.050
1.060
1.070
1.080
1.090
1.100
Safe operating temperature
Freezingtemperature
Concentrationof coolant
Specific gravityof coolant
Coolant temperature
B
A
C
-40(-40) (-22)(-4)(14)(32)(50) (68) (86)
( F)
(104)-30-20 -10010203040
(77 F)
50%
40%
30%
20%
25 C
10%
C

CO(H6DO)-12
Engine Coolant
COOLING
2. PROCEDURE TO ADJUST THE CON-
CENTRATION OF THE COOLANT
To adjust the concentration of coolant according to
temperature, find the proper fluid concentration in
the above diagram and replace the necessary
amount of coolant with an undiluted solution of
SUBARU Genuine Coolant (concentration 50%).
The amount of engine coolant that should be re-
placed can be determined using the diagram.
[Example]
Assume that the engine coolant concentration must
be increased from 25% to 40%. Find point A, where
the 25% line of engine coolant concentration inter-
sects with the 40% curve of the necessary engine
coolant concentration, and read the scale on the
vertical axis of the graph at height A. The quantity
of coolant to be drained is 2.12;(2.2 US qt, 1.8 Imp
qt). Drain 2.1 2(2.2 US qt, 1.8 Imp qt) of coolant
from the cooling system and add 2.1 2(2.2 US qt,
1.8 Imp qt) of the undiluted solution of SUBARU
coolant.
If a coolant concentration of 50% is needed, drain
all the coolant and refill with the undiluted solution
only.
CO-00012
100
1
2
3
(1.1, 0.9)
(2.1, 1.8)
(3.2, 2.6)
10%15%
25%20%
30%
35%40%
45%A
20 30 40 50
Concentration of coolant in vehicieand quantity to be drained
Quantity of coolant to bedrained (US qt, Imp qt)
Necessary Concentrationof coolant
Concentration of coolant inthe vehicie cooling system %

CO(H6DO)-13
Water Pump
COOLING
4. Water Pump
A: REMOVAL
1) Remove the radiator.
2) Remove the V-belts.
3) Remove the front chain cover.
4) Remove the timing chain assembly.
5) Remove the water pump.
NOTE:
When the water pump cannot be removed easily,
screw-in the bolt (A) to the threaded end to remove
water pump.
B: INSTALLATION
1) Install the water pump to rear chain cover.
NOTE:
Apply engine coolant to O-ring.
Tightening torque
6.4 N·m (0.65 kgf-m, 4.7 ft-lb)
NOTE:
•Use new O-rings.
•Apply engine coolant to O-ring to install water
pump easier.
2) Install the timing chain assembly.
3) Install the front chain cover.
4) Install the V-belts.
5) Install the radiator.
6) Fill engine coolant.
MENT, Engine Coolant.>
C: INSPECTION
1) Check the water pump bearing for smooth rota-
tion.
2) Check the water pump sprocket for abnormali-
ties.
CO-02013
(A)
(A)
CO-02014

CO(H6DO)-14
Thermostat
COOLING
5. Thermostat
A: REMOVAL
1) Set the vehicle on a lift.
2) Lift-up the vehicle.
3) Remove the under cover.
4) Drain engine coolant completely.
5) Disconnect the radiator hose from thermostat
cover.
6) Remove the thermostat cover, and then remove
the thermostat.
B: INSTALLATION
1) Install a gasket to thermostat.
NOTE:
Use a new gasket.
2) Install the thermostat and thermostat cover.
NOTE:
The thermostat must be installed with the jiggle pin
facing to the up side.
Tightening torque:
6.4 N·m (0.65 kgf-m, 4.7 ft-lb)
3) Connect the radiator hose to thermostat cover.
4) Install the under cover.
5) Lower the vehicle.
6) Fill engine coolant.
MENT, Engine Coolant.>
C: INSPECTION
Replace the thermostat if the valve does not close
completely at an ambient temperature or if the fol-
lowing test shows unsatisfactory results.
•Inspection method
Immerse the thermostat and a thermometer in wa-
ter. Raise water temperature gradually, and mea-
sure the temperature and valve lift when the valve
begins to open and when the valve is fully opened.
During the test, agitate the water for even temper-
ature distribution. The measured value should
meet the specification.
Starting temperature to open:
80 — 84°C (176 — 183°F)
Fully opens:
95°C (203°F)
NOTE:
•Leave the thermostat in the boiling water for
more than five minutes before measuring the
valve lift.
•Hold the thermostat with a wire or the like to
avoid contacting with container bottom.
Valve lift:
9.0 mm (0.354 in) or more
CO-02015
CO-02016
CO-02016
(A) Thermometer
(B) Thermostat
CO-00033
(A)
(B)