Subaru Legacy III (2000-2003 year). Manual — part 479

EN(H4DOSTC)-86

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

7

CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness

between ECM and intake manifold pres-
sure sensor connector.

Connector & terminal

(B135) No. 19 — (E21) No. 2:

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

1

Ω

Go to step 8.

Repair the open
circuit in harness
between ECM and
intake manifold
pressure sensor
connector.

8

CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
Measure the resistance of harness between
intake manifold pressure sensor connector and
engine ground.

Connector & terminal

(E21) No. 1 — Engine ground:

Does the measured value exceed the specified
value?

1 M

Ω

Go to step 9.

Repair the ground
short circuit in har-
ness between
ECM and intake
manifold pressure
sensor connector.

9

CHECK POOR CONTACT.
Check poor contact in pressure sensor con-
nector.
Is there poor contact in pressure sensor con-
nector?

There is poor contact.

Repair the poor
contact in pres-
sure sensor con-
nector.

Replace the pres-
sure sensor. <Ref.
to FU(H4DOSTC)-
34, Pressure Sen-
sor.>

Step

Value

Yes

No

EN(H4DOSTC)-87

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

MEMO:

EN(H4DOSTC)-88

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

H: DTC P0108 — MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRES-

SURE CIRCUIT HIGH INPUT —

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOSTC)-35,
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOSTC)-33, Inspection
Mode.> .
• WIRING DIAGRAM:

EN-00935

B122

PRESSURE SENSOR

THROTTLE BODY

3

2

1

19

9

8

ECM

B135

E21

E2

B21

1
6

20

18

16

1 2 3

B122

B21

E21

1 2 3 4 5 6

1 2

5

6 7

8

13

14 15

16

9 10

11 12

3 4

17 18

19 20

B135

5 6

7 8

2

1

9

4

3

10

24

22

23

25

11 12 13 14 15

26 27 28

16 17 18 19

20 21

EN(H4DOSTC)-89

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of intake manifold absolute

pressure signal using Subaru Select Moni-
tor.
Does the measured value exceed the spec-
ified value?

NOTE:

For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOSTC)-26, Subaru Select Monitor.>

282 kPa (2121 mmHg, 83.50
inHg)

Go to step 7.

Go to step 2.

2

CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.

Connector & terminal

(B135) No. 9 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the specified
value?

4.5 V

Go to step 4.

Go to step 3.

3

CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.

Connector & terminal

(B135) No. 9 (+) — Chassis ground (

−−−−

):

Does the measured value change by shaking
harness and connector of ECM while monitor-
ing the value with voltage meter?

The value changes.

Repair the poor
contact in ECM
connector.

Contact SUBARU
distributor service.

NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.

4

CHECK INPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.

Connector & terminal

(B135) No. 8 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified
value?

4.5 V

Go to step 5.

Contact SUBARU
distributor service.

NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.

5

CHECK HARNESS BETWEEN ECM AND
PRESSURE SENSOR CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from pressure

sensor.

3) Turn the ignition switch to ON.
4) Measure the voltage between pressure

sensor connector and engine ground.

Connector & terminal

(E21) No. 3 (+) — Engine ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

4.5 V

Go to step 6.

Repair the open
circuit in harness
between ECM and
pressure sensor
connector.