Subaru Legacy III (2000-2003 year). Manual — part 480

EN(H4DOSTC)-90

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

6

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 pressure sensor con-
nector.

Connector & terminal

(B135) No. 8 — (E21) No. 1:
(B135) No. 19 — (E21) No. 2:

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

1

Ω

Go to step 7.

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

7

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)-91

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

MEMO:

EN(H4DOSTC)-92

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

I:

DTC P0112 — INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT —

• TROUBLE SYMPTOM:

• Erroneous idling
• Poor driving performance

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-00951

B122

B3

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

BATTERY

E

B122

1

B3

MASS AIR FLOW AND
INTAKE AIR TEMPERATURE

ECM

B135

B :

B84

E :

SBF-5

1 2 3 4 5

3

4

1

2

5

6

1 2 3 4 5 6

B84

B47

2
6

2

4

3

5

E7

B27

E13

B19

E8

1 2 3

8 9 10

4

11 12

13 14 15

16

5 6

7

17

MAIN RELAY

B47

1

2

3

5

4

6

EN(H4DOSTC)-93

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 air temperature

sensor signal using Subaru Select Monitor.
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.>

55

°

C (131

°

F)

Go to step 2.

Repair the poor
contact.

NOTE:
In this case, repair
the following:
• Poor contact
mass air flow and
intake air tempera-
ture sensor
• Poor contact in
ECM
• Poor contact in
joint connector

2

CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mass air

flow and intake air temperature sensor.

3) Turn the ignition switch to ON.
4) Read the data of intake air temperature

sensor signal using Subaru Select Monitor.
Is the measured value less than the speci-
fied value?

NOTE:

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

−

36

°

C (

−

97

°

F)

Replace the mass
air flow and intake
air temperature
sensor. <Ref. to
FU(H4DOSTC)-
33, Mass Air Flow
and Intake Air
Temperature Sen-
sor.>

Repair the ground
short circuit in har-
ness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector.