Subaru Legacy III (2000-2003 year). Manual - part 333

EN(H6DO)-134

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

L: DTC P0111 — INTAKE AIR TEMPERATURE CIRCUIT RANGE/PERFOR-

MANCE —

• DTC DETECTING CONDITION:

• Two consecutive driving cycles with fault

• TROUBLE SYMPTOM:

• Erroneous idling
• Poor driving performance

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-00812

13

10

B20

E1

INTAKE AIR

TEMPERATURE 

SENSOR

E20

B20

27

19

B135

B83

1

2

E20

5

8

ECM

B83

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

1 2

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

1 2 3 4

5 6 7 8 9 10

11 12

19 20

13 14 15 16 17 18

EN(H6DO)-135

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

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).>

NOTE:
In this case, it is
not necessary to
inspect DTC
P0111.

Replace intake air 
temperature sen-
sor. <Ref. to 
FU(H6DO)-35, 
Intake Air Temper-
ature Sensor.>

EN(H6DO)-136

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

M: DTC P0112 — INTAKE AIR TEMPERATURE CIRCUIT LOW INPUT —

• 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(H6DO)-54, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)-47, OPERATION, Inspec-
tion Mode.>.

• WIRING DIAGRAM:

EN-00812

13

10

B20

E1

INTAKE AIR

TEMPERATURE 

SENSOR

E20

B20

27

19

B135

B83

1

2

E20

5

8

ECM

B83

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

1 2

1 2 3 4
5 6 7 8
9 10 11 12

13 14 15 16

1 2 3 4

5 6 7 8 9 10

11 12

19 20

13 14 15 16 17 18

EN(H6DO)-137

ENGINE (DIAGNOSTICS)

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)

Step

Value

Yes

No

1

CHECK CURRENT DATA.
1) Start engine.
2) Read data of intake air temperature sensor 

signal using Subaru Select Monitor or the 
OBD-II general scan tool.
Does the measured value exceed the spec-
ified value?

NOTE:

• Subaru Select Monitor
For detailed operation procedure, refer to the 
“READ CURRENT DATA FOR ENGINE”. 
<Ref. to EN(H6DO)-34, Subaru Select Moni-
tor.>
• OBD-II general scan tool
For detailed operation procedure, refer to the 
OBD-II General Scan Tool Instruction Manual.

120

°

C (248

°

F)

Go to step 2.

Repair poor con-
tact.

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

2

CHECK HARNESS BETWEEN INTAKE AIR 
TEMPERATURE SENSOR AND ECM CON-
NECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from intake air tem-

perature sensor.

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

signal using Subaru Select Monitor or the 
OBD-II general scan tool.
Is the measured value less than the speci-
fied value?

NOTE:

• Subaru Select Monitor
For detailed operation procedure, refer to the 
“READ CURRENT DATA FOR ENGINE”. 
<Ref. to EN(H6DO)-34, Subaru Select Moni-
tor.>
• OBD-II general scan tool
For detailed operation procedure, refer to the 
OBD-II General Scan Tool Instruction Manual.

−

40

°

C (

−

40

°

F)

Replace intake air 
temperature sen-
sor. <Ref. to 
FU(H6DO)-35, 
Intake Air Temper-
ature Sensor.>

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