Subaru Legacy (2005 year). Service manual — part 204

EN(H4SO 2.5)(diag)-101

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

J: DTC P0112 INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT LOW

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
• Erroneous idling
• Poor driving performance

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO 2.5)(diag)-
40, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO 2.5)(diag)-33, Inspection Mode.>.
WIRING DIAGRAM:
• EC, EK, EH, ER and K4 model

• KA and KS model

NOTE:
Fuel injection system for KA and KS model is the same as 2.0 L model. Refer to EN(H4SO 2.0) section.

EN-03459

B3

BATTERY

E

1

B3

MASS AIR FLOW AND

INTAKE AIR TEMPERATURE

SENSOR

ECM

B136

SBF-7

3

4

1

2

5

6

B47

2

4

3

5

31

13

23

35

32

MAIN RELAY

B47

1

2

6

3

5

1 2 3 4
5 6 7 8

B83

B136

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

33 34

29

32

30

31

35

*

: TERMINAL No. RANDOM ARRANGEMENT

B83

*

1 2 3 4 5

4

*

EN(H4SO 2.5)(diag)-102

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK OPTION CODE.

Is the option code EC, EK, EH,
ER or K4?

Go to step 2.

Refer to EN(H4SO
2.0) section. <Ref.
to EN(H4SO
2.0)(diag)-64, List
of Diagnostic Trou-
ble Code (DTC).>

NOTE:
Fuel injection sys-
tem for KA and KS
model is the same
as 2.0 L model.

2

CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of mass air flow and intake
air temperature sensor signal using Subaru
Select Monitor or general scan tool.

NOTE:

• Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.5)(diag)-25, Subaru Select
Monitor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.

Is the intake air temperature
more than 120

°C (248°F)?

Go to step 3.

Repair the poor
contact.

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

3

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 mass air flow and intake
air temperature sensor signal using Subaru
Select Monitor or general scan tool.

NOTE:

• Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.5)(diag)-25, Subaru Select
Monitor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.

Is the intake air temperature
less than

−40°C (−40°F)?

Replace the mass
air flow and intake
air temperature
sensor. <Ref. to
FU(H4SO 2.5)-26,
Mass Air Flow and
Intake Air Temper-
ature Sensor.>

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

EN(H4SO 2.5)(diag)-103

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

K: DTC P0113 INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT HIGH

DTC DETECTING CONDITION:
Immediately at fault recognition
TROUBLE SYMPTOM:
• Erroneous idling
• Poor driving performance

CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO 2.5)(diag)-
40, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO 2.5)(diag)-33, Inspection Mode.>.
WIRING DIAGRAM:
• EC, EK, EH, ER and K4 model

• KA and KS model

NOTE:
Fuel injection system for KA and KS model is the same as 2.0 L model. Refer to EN(H4SO 2.0) section.

EN-03459

B3

BATTERY

E

1

B3

MASS AIR FLOW AND

INTAKE AIR TEMPERATURE

SENSOR

ECM

B136

SBF-7

3

4

1

2

5

6

B47

2

4

3

5

31

13

23

35

32

MAIN RELAY

B47

1

2

6

3

5

1 2 3 4
5 6 7 8

B83

B136

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

33 34

29

32

30

31

35

*

: TERMINAL No. RANDOM ARRANGEMENT

B83

*

1 2 3 4 5

4

*

EN(H4SO 2.5)(diag)-104

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK OPTION CODE.

Is the option code EC, EK, EH,
ER or K4?

Go to step 2.

Refer to EN(H4SO
2.0) section. <Ref.
to EN(H4SO
2.0)(diag)-64, List
of Diagnostic Trou-
ble Code (DTC).>

NOTE:
Fuel injection sys-
tem for KA and KS
model is the same
as 2.0 L model.

2

CHECK CURRENT DATA.
1) Start the engine.
2) Read the data of mass air flow and intake
air temperature sensor signal using Subaru
Select Monitor or general scan tool.

NOTE:

• Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.5)(diag)-25, Subaru Select
Monitor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.

Is the intake air temperature
less than

−40°C (−40°F)?

Go to step 3.

Repair the poor
contact.

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

3

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) Measure the voltage between mass air flow
and intake air temperature sensor connector
and engine ground.

Connector & terminal

(B3) No. 4 (+) — Engine ground (

−

):

Is the voltage more than 10 V? Repair the battery

short circuit of har-
ness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector.

Go to step 4.

4

CHECK HARNESS BETWEEN MASS AIR
FLOW AND INTAKE AIR TEMPERATURE
SENSOR AND ECM CONNECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between mass air flow
and intake air temperature sensor connector
and engine ground.

Connector & terminal

(B3) No. 4 (+) — Engine ground (

−

):

Is the voltage more than 10 V? Repair the battery

short circuit of har-
ness between
mass air flow and
intake air tempera-
ture sensor and
ECM connector.

Go to step 5.