Subaru Legacy III (2000-2003 year). Manual — part 339

EN(H6DO)-158

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

U: DTC P0129 — BAROMETRIC PRESSURE TOO LOW —

• DTC DETECTING CONDITION:

• Two consecutive driving cycles with fault

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H6DO)-54, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)-47, OPERATION, Inspec-
tion Mode.>.

Step

Value

Yes

No

1

CHECK ANY OTHER DTC ON DISPLAY.
Is any other DTC displayed?

Another DTC is displayed.

Inspect the rele-
vant DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
EN(H6DO)-89, List
of Diagnostic
Trouble Code
(DTC).>

Replace ECM.
<Ref. to
FU(H6DO)-46,
Engine Control
Module.>

NOTE:
Atmospheric pres-
sure sensor is built
into ECM.

EN(H6DO)-159

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

MEMO:

EN(H6DO)-160

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

V: DTC P0130 — O2 SENSOR CIRCUIT (BANK 1 SENSOR 1) —

• DTC DETECTING CONDITION:

• Immediately at fault recognition

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H6DO)-54, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)-47, OPERATION, Inspec-
tion Mode.>.

• WIRING DIAGRAM:

EN-01087

BATTERY

F44

B61

SBF-5

6

B47

MAIN RELAY

1

2

3

5

4

6

9

8

21

31

2

1

5

B252

E49

ECM

18

29

19

5

4

7

6

20

30

4

1

3

FRONT

OXYGEN

(A/F)

SENSOR RH

E47

2

4

3

1

FRONT

OXYGEN

(A/F)

SENSOR LH

E24

B137

E3

B22

B83

11

8

1

2

3

E2

B21

2

3

E2

B21

20

19

E49

B252

4

8

LHD

RHD

LHD

RHD

B252

B47

3

4

5

6

1

2

E24

E47

B137

1

2

7

8

9

5

6

3

4

10 11 12

19 20 21
29 30 31

13 14 15 16 17

27 28

18

22 23 24 25 26

1 2 3 4
5 6 7 8

3

4

1

2

1 2 3 4
5 6 7 8

F44

B21

1 2

5

6 7

8

13

14 15

16

9 10

11 12

3 4

17 18

19 20

B83

1 2 3 4

5 6 7 8 9 10

11 12

19

20

13 14 15 16 17 18

EN(H6DO)-161

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK DTC ON DISPLAY.
Are P0130 and P0134 displayed at the same
time?

∆ισπλαψεδ

Go to step 3.

Go to step 2.

2

CHECK HARNESS BETWEEN ECM AND
FRONT O2 (A/F) SENSOR CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM and front

O2 (A/F) sensor.

3) Measure resistance of harness between

ECM connectors.

Connector & terminal

(B137) No. 29 — (B137) No. 19:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 3.

Repair ground
short circuit in har-
ness between
ECM and front
oxygen O2 (A/F)
sensor connector.

3

CHECK INPUT SIGNAL FOR ECM.
1) Connect ECM and front O2 (A/F) sensor

connector.

2) Turn ignition switch to ON.
3) After warming up engine, idle engine.
4) Measure voltage between ECM connector

and chassis ground.

Connector & terminal

(B137) No. 29 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

3.5 — 4.5 V

Go to step 4.

Repair power
short circuit in har-
ness, when 4.5 V
or more. Repair
ground short cir-
cuit in harness,
when 3.5 V or
less.

4

CHECK ECM INPUT VOLTAGE.
Measure voltage between ECM connector and
body ground.

Connector & terminal

(B137) No. 19 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

2.5 — 4.95 V

Replace front O2
(A/F) sensor.

Repair power
short circuit in har-
ness, when 4.95 V
or more. Repair
ground short cir-
cuit in harness,
when 2.5 V or
less.