Subaru Legacy III (2000-2003 year). Manual - part 169

EN(H4SO)-288

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

CL:DTC P1517 — ISC SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION 

(HIGH INPUT) —

• DTC DETECTING CONDITION:

• Immediately at fault recognition

• TROUBLE SYMPTOM:

• Erroneous idling
• Engine stalls.
• Engine breathing

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode<Ref. to EN(H4SO)-47, OPER-
ATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)-40, OPERATION, Inspection 
Mode.> .
• WIRING DIAGRAM:

EN-01134

F44

B61

6

RHD

RHD

20

6

5

19

B21

E2

ECM

2

5

6

3

4

1

3

4

1

2

IDLE 

AIR CONTROL

SOLENOID 

VALVE

E7

B22

E3

B47

B134

B47

3

4

1

2

5

6

B134

1 2

3 4

5 6

7 8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

24 25

26 27 28 29

30 31 32 33

34 35

B22

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

E7

1

3

4 5 6

2

B21

1 2

3 4

5

6 7

8

9 10

11 12

13

14 15

16

17 18

19 20

SBF-5

BATTERY

MAIN RELAY

1

2

3

5

4

6

1

1 2 3 4
5 6 7 8

F44

LHD

LHD

EN(H4SO)-289

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK ANY OTHER DTC ON DISPLAY.
Does the Subaru Select Monitor or OBD-II 
general scan tool indicate DTC P1511, P1513, 
P1515 and P1517 at same time?

Indicated at same time.

Go to step 2.

Go to step 3.

2

CHECK GROUND CIRCUIT FOR ECM.
1) Turn ignition switch to OFF.
2) Measure resistance between ECM connec-

tor and chassis ground.

Connector & terminal

(B134) No. 7 — Chassis ground:

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

5 

Ω

Go to step 3.

Repair harness 
and connector.

NOTE:
In this case, repair
the following:
• Open circuit in 
harness between 
ECM connector 
and engine ground 
terminal
• Poor contact in 
ECM connector
• Poor contact in 
coupling connector

3

CHECK HARNESS BETWEEN ECM AND 
IDLE AIR CONTROL SOLENOID VALVE 
CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from idle air control 

solenoid valve.

3) Turn ignition switch to ON.
4) Measure voltage between ECM connector 

and chassis ground.

Connector & terminal

DTC P1511; (B134) No. 20 (+) — Chas-
sis ground (–):
DTC P1513; (B134) No. 6 (+) — Chassis 
ground (–):
DTC P1515; (B134) No. 5 (+) — Chassis 
ground (–):
DTC P1517; (B134) No. 19 (+) — Chas-
sis ground (–):

Does the measured value exceed the spec-
ified value?

10 V

Repair battery 
short circuit in har-
ness between 
ECM and idle air 
control solenoid 
valve connector. 
After repair, 
replace ECM.  
<Ref. to 
FU(H4SO)-45, 
Engine Control 
Module.>

Replace ECM.  
<Ref. to 
FU(H4SO)-45, 
Engine Control 
Module.>

EN(H4SO)-290

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

CM:DTC P1518 — STARTER SWITCH CIRCUIT LOW INPUT —

• DTC DETECTING CONDITION:

• Two consecutive driving cycles with fault

• TROUBLE SYMPTOM:

• Failure of engine to start

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode<Ref. to EN(H4SO)-47, OPER-
ATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)-40, OPERATION, Inspection 
Mode.> .

EN(H4SO)-291

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

• WIRING DIAGRAM:

EN-01118

12

INHIBITOR SWITCH

STARTER
MOTOR

7

P

R

N

D

3

2

1

SBF-4

SBF-1

B14

B72

12

11

T7

T3

B12

1
3

IGNITION
SWITCH

AT

MT

AT

MT

T7

1 2 3 4 5 6
7 8 9 10 11 12

B72

3 4

1 2

20

B136

ECM

BATTERY

B12

1 2 3 4
5 6 7 8
9 10 11 12

B136

5 6

7

2

1

9

8

4

3

23

21 22

24

10 11 12 13 14

25 26

15 16 17

18 19 20