Subaru Legacy III (2000-2003 year). Manual - part 76

CO(H4SO)-12

COOLING

RADIATOR SUB FAN SYSTEM

5

CHECK POWER SUPPLY TO SUB FAN RE-
LAY.
1) Turn ignition switch to OFF.
2) Remove sub fan relay from A/C relay 

holder.

3) Measure voltage between sub fan relay ter-

minal and chassis ground.

Connector & terminal

(F28) No. 21 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Go to step 6.

Go to step 7.

6

CHECK POWER SUPPLY TO SUB FAN RE-
LAY.
1) Turn ignition switch to ON.
2) Measure voltage between sub fan relay ter-

minal and chassis ground.

Connector & terminal

(F28) No. 24 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Go to step 10.

Go to step 9.

7

CHECK 20 A FUSE.
1) Remove 20 A fuse from A/C relay holder.
2) Check condition of fuse.

Is the fuse blown-out?

Fuse is blown-out.

Replace fuse.

Go to step 8.

8

CHECK POWER SUPPLY TO A/C RELAY 
HOLDER 20 A FUSE TERMINAL.
Measure voltage of harness between A/C relay 
holder 20 A fuse terminal and chassis ground.

Connector & terminal

(F27) No. 3 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the specified 
value?

10 V

Repair open circuit 
in harness 
between 20 A fuse 
and sub fan relay 
terminal.

Repair open circuit 
in harness 
between main fuse 
box connector and 
20 A fuse terminal.

9

CHECK FUSE.
1) Turn ignition switch to OFF.
2) Remove fuse No. 17 from joint box.
3) Check condition of fuse.

Is the fuse blown-out?

Fuse is blown-out.

Replace fuse.

Repair open circuit 
in harness 
between sub fan 
relay and ignition 
switch.

10

CHECK SUB FAN RELAY.
1) Turn ignition switch to OFF.
2) Measure resistance of sub fan relay.

Terminal

 No. 20 — No. 21:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 11.

Replace sub fan 
relay.

11

CHECK SUB FAN RELAY.
1) Connect battery to terminals No. 22 and 

No. 24 of sub fan relay.

2) Measure resistance of sub fan relay.

Terminal

 No. 20 — No. 21:

Is the measured value less than the speci-
fied valve?

1 

Ω

Go to step 12.

Replace sub fan 
relay.

Step

Value

Yes

No

CO(H4SO)-13

COOLING

RADIATOR SUB FAN SYSTEM

NOTE:
Inspection by SUBARU distributor service is required, because probable cause is deterioration of multiple
parts.

12

CHECK HARNESS BETWEEN SUB FAN RE-
LAY TERMINAL AND SUB FAN MOTOR 
CONNECTOR.
Measure resistance of harness between sub 
fan motor connector and sub fan relay termi-
nal.

Connector & terminal

(F16) No. 2 — (F28) No. 20:

Is the measured value less than the specified 
valve?

1 

Ω

Go to step 13.

Repair open circuit 
in harness 
between sub fan 
motor and sub fan 
relay connector.

13

CHECK HARNESS BETWEEN SUB FAN RE-
LAY AND ECM.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between 

sub fan relay connector and ECM connec-
tor.

Connector & terminal

With OBD

(F28) No. 22 — (B134) No. 13:

Without OBD

(F28) No. 22 — (B134) No. 12:

Is the measured value less than the speci-
fied valve?

1 

Ω

Go to step 14.

Repair open circuit 
in harness 
between sub fan 
relay and ECM.

14

CHECK POOR CONTACT.
Check poor contact in connector between sub 
fan and ECM.
Is there poor contact in connector between sub 
fan motor and ECM?

There is poor contact.

Repair poor con-
tact connector.

Contact with SUB-
ARU distributor 
service.

Step

Value

Yes

No

CO(H4SO)-14

COOLING

ENGINE COOLANT

4. Engine Coolant

A: REPLACEMENT

1. DRAINING OF ENGINE COOLANT

1) Lift-up the vehicle.
2) Remove under cover.

3) Remove drain cock to drain engine coolant into
container.

NOTE:
Remove radiator cap so that engine coolant will
drain faster.

2. FILLING OF ENGINE COOLANT

1) Fill engine coolant into radiator up to filler neck
position.

Engine coolant amount for refill:

2.0 L MT ;

Approx. 7.0 

2

 (7.4 US qt, 6.2 Imp qt)

2.0 L AT ;

Approx. 6.9 

2

 (7.3 US qt, 6.1 Imp qt)

2.5 L MT ;

Approx. 6.8 

2

 (7.2 US qt, 6.0 Imp qt)

2.5 L AT ;

Approx. 6.7 

2

 (7.1 US qt, 5.9 Imp qt)

CAUTION:
The SUBARU Genuine Coolant containing anti-
freeze and anti-rust agents is especially made 
for SUBARU engine, which has an aluminum 
crankcase. Always use SUBARU Genuine Cool-
ant, since other coolant may cause corrosion.

2) Fill engine coolant into reservoir tank up to upper
level.

3) Attach radiator cap and reservoir tank cap prop-
erly.
4) Warm-up engine completely for more than five
minutes at 2,000 to 3,000 rpm.
5) If engine coolant level drops in radiator, add en-
gine coolant to filler neck position.
6) If engine coolant level drops from upper level of
reservoir tank, add engine coolant to upper level.
7) Attach radiator cap and reservoir tank cap prop-
erly.

LU-00095

CO-00083

CO-00010

FULL

LOW

Full level

Low level

CO(H4SO)-15

COOLING

ENGINE COOLANT

B: INSPECTION

1. RELATIONSHIP OF SUBARU COOLANT 
CONCENTRATION AND FREEZING TEM-
PERATURE

The concentration and safe operating temperature
of the SUBARU coolant is shown in the diagram.
Measuring 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).

2. PROCEDURE TO ADJUST THE CON-
CENTRATION OF THE COOLANT

To adjust the concentration of the coolant accord-
ing to temperature, find the proper fluid concentra-
tion in the above diagram and replace the
necessary amount of coolant with an undiluted so-
lution of SUBARU genuine coolant (concentration
50).
The amount of coolant that should be replaced can
be determined using the diagram.
[Example]
Assume that the coolant concentration must be in-
creased from 25% to 40%. Find point A, where the
25% line of coolant concentration intersects with
the 40% curve of the necessary coolant concentra-
tion, and read the scale on the vertical axis of the
graph at height A. The quantity of coolant to be
drained is 2.1 liters (2.2 US qt, 1.8 Imp qt). Drain
2.1 liters (2.2 US qt, 1.8 Imp qt) of coolant from the
cooling system and add 2.1 liters (2.2 US qt, 1.8
Imp qt) of the undiluted solution of SUBARU cool-
ant.
If a coolant concentration of 50% is needed, drain
all the coolant and refill with the undiluted solution
only.

CO-00062

1.000

1.010

  –40

  (–40)

1.020

1.030

1.040

1.050

1.060

(1.054)

1.070

C

B

A

1.080

1.090

1.100

  –30

  (–22)

  –20

  (–4)

  –10

  (14)

  0

  (32)

  10

10%

20%

 30%

40%

50%

60%

  (50)

  20

25

˚C

(77

˚F)

  (68)

  30

  (86)

  40

  (104)

  50

  (122)

Specific gravity

of coolant

Safe operating temperature

Concentration
of coolant

Freezing
temperature

Coolant temperature ˚C (˚F)

CO-00063

  10

0

1

(1.1,

  0.9)

(2.1,

  1.8)

(3.2,

  2.6)

2

45%

40%

35%

30%

25%

20%

15%

10%

 20

30

40

50

3

A

Quantity of coolant to be 

drained   (US qt, lmp qt) 

Necessary concentration 
of coolant

Concentration of coolant in 
the vehicle cooling system %

Concentration of coolant in vehicle 
  and quantity to be drained