Subaru Legacy (2005 year). Manual — part 235

EN(H4SO 2.5)(diag)-225

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

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-03512

B362

E57

B362

B20

B21

E57

B122

B83

B138

1 2

7 8

3
4

5
6

1 2 3 4 5 6 7 8 9 10 11

12 13 14 15 16 17 18 19 20 21 22
23 24 25

34 35

36 37 38 39 40 41

48 49

50 51 52 53 54

42 43

44 45

46 47

26 27 28 29 30 31 32 33

1 2 3 4
5 6 7 8

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

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

32 33

34 35

1

2

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

7

32 33 34 35

B135

B:

B136

C:

B137

D:

BATTERY

MAIN RELAY

ELECTRONIC
THROTTLE
CONTROL RELAY

ELECTRONIC
THROTTLE CONTROL

SBF-7

B135

B:

B137

B136

D:

E1

B20

B83

C:

E

E

E

D6

B35

38

39

20

19

16

15

E2

B21

4

6

1

2

3

5

D4

D5

C35

C16

B1

B4

D1

D2

D3

36

35

37

C29

C18

ECM

5

8

7

6

36

B21

E2

E

B122 : RHD

B138 : LHD

1 2 3 4 5 6

B138 : RHD

B122 : LHD

1 2 3 4
5 6 7 8
9 10 11 12

14

13

15 16

*

: TERMINAL No. RANDOM ARRANGEMENT

1

*

: TERMINAL No. RANDOM ARRANGEMENT
AMONG 1,2,5, AND 6

2

*

1

*

2

*

1

*

1

*

1

*

2

EN(H4SO 2.5)(diag)-226

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 ELECTRONIC THROTTLE CON-
TROL RELAY.
1) Turn the ignition switch to OFF.
2) Remove the electronic throttle control relay.
3) Connect the battery to terminals No. 5 and
No. 6 of electronic throttle control relay.
4) Measure the resistance between electronic
throttle control relay terminals.

Terminals

No. 7 — No. 8:

Is the resistance less than 1
Ω?

Go to step 3.

Replace the elec-
tronic throttle con-
trol relay.

3

CHECK POWER SUPPLY OF ELECTRONIC
THROTTLE CONTROL RELAY.
1) Turn the ignition switch to ON.
2) Measure the voltage between electronic
throttle control relay connector and chassis
ground.

Connector & terminal

(B362) No. 8 (+) — Chassis ground (

−

):

(B362) No. 5 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Go to step 4.

Repair the open or
ground short cir-
cuit of power sup-
ply circuit.

4

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL RE-
LAY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Turn the ignition switch to ON.
4) Measure the voltage between electronic
throttle control relay connector and chassis
ground.

Connector & terminal

(B362) No. 6 (+) — Chassis ground (

−

):

Is the voltage more than 10 V? Repair the power

supply short cir-
cuit of harness
between ECM and
electronic throttle
control.

Go to step 5.

5

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL RE-
LAY.
1) Turn the ignition switch to OFF.
2) Measure the resistance between electronic
throttle control relay connector and chassis
ground.

Connector & terminal

(B362) No. 6 — Chassis ground:
(B362) No. 7 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 6.

Repair the ground
short circuit of har-
ness between
ECM and elec-
tronic throttle con-
trol relay.

6

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL RE-
LAY.
Measure the resistance between ECM connec-
tor and electronic throttle control relay connec-
tor.

Connector & terminal

(B135) No. 35 — (B362) No. 6:
(B137) No. 6 — (B362) No. 7:

Is the resistance less than 1
Ω?

Go to step 7.

Repair the open
circuit of harness
between ECM and
electronic throttle
control relay.

EN(H4SO 2.5)(diag)-227

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

7

CHECK SENSOR OUTPUT.
1) Connect all the connectors.
2) Turn the ignition switch to ON.
3) Read the data of main throttle sensor signal
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.5)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage more than 0.4 V? Go to step 8.

Go to step 10.

8

CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.5)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage more than 0.8 V? Go to step 9.

Go to step 10.

9

CHECK POOR CONTACT.
Check poor contact in connector between
ECM and electronic throttle control.

Is there poor contact?

Repair the poor
contact.

Go to step 14.

10

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from electronic
throttle control.
4) Measure the resistance between ECM con-
nector and electronic throttle control connector.

Connector & terminal

(B136) No. 18 — (E57) No. 6:
(B136) No. 29 — (E57) No. 4:
(B136) No. 16 — (E57) No. 5:

Is the resistance less than 1
Ω?

Go to step 11.

Repair the open
circuit of harness
connector.

11

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
Measure the resistance between ECM connec-
tor and chassis ground.

Connector & terminal

(B136) No. 16 — Chassis ground:
(B136) No. 18 — Chassis ground:
(B136) No. 29 — Chassis ground:

Is the resistance more than 1
M

Ω?

Go to step 12.

Repair the ground
short circuit of har-
ness.

12

CHECK SENSOR POWER SUPPLY.
1) Connect the ECM connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic
throttle control connector and engine ground.

Connector & terminal

(E57) No. 5 (+) — Engine ground (

−

):

Is the voltage 4.5 — 5.5 V?

Go to step 13.

Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.5)-
37, Engine Con-
trol Module
(ECM).>

13

CHECK SHORT CIRCUIT INSIDE THE ECM.
1) Turn the ignition switch to OFF.
2) Measure the resistance between electronic
throttle control connector and engine ground.

Connector & terminal

(E57) No. 6 — Engine ground:
(E57) No. 4 — Engine ground:

Is the resistance more than 10
Ω?

Go to step 14.

Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.5)-
37, Engine Con-
trol Module
(ECM).>

Step

Check

Yes

No

EN(H4SO 2.5)(diag)-228

ENGINE (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

14

CHECK SENSOR OUTPUT.
1) Connect all the connectors.
2) Turn the ignition switch to ON.
3) Read the data of main throttle sensor signal
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.5)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage less than 4.63
V?

Go to step 15.

Go to step 17.

15

CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal
using Subaru Select Monitor.

NOTE:

For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.5)(diag)-25, Subaru Select Mon-
itor.>

Is the voltage less than 4.73
V?

Go to step 16.

Go to step 17.

16

CHECK POOR CONTACT.
Check poor contact in connector between
ECM and electronic throttle control.

Is there poor contact?

Repair the poor
contact.

Go to step 22.

17

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from electronic
throttle control.
4) Measure the resistance between ECM con-
nector and electronic throttle control connector.

Connector & terminal

(B136) No. 35 — (E57) No. 3:
(B136) No. 18 — (E57) No. 6:
(B136) No. 29 — (E57) No. 4:

Is the resistance less than 1
Ω?

Go to step 18.

Repair the open
circuit of harness
connector.

18

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Connect the ECM connector.
2) Measure the resistance between electronic
throttle control connector and engine ground.

Connector & terminal

(E57) No. 3 — Engine ground:

Is the resistance less than 5
Ω?

Go to step 19.

Repair the poor
contact in ECM
connector.
Replace the ECM
if defective. <Ref.
to FU(H4SO 2.5)-
37, Engine Con-
trol Module
(ECM).>

19

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to ON.
2) Measure the voltage between electronic
throttle control connector and engine ground.

Connector & terminal

(E57) No. 5 (+) — Engine ground (

−

):

Is the voltage less than 10 V?

Go to step 20.

Repair the battery
short circuit of har-
ness between
ECM connector
and electronic
throttle control
connector.

20

CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
Measure the voltage between electronic throt-
tle control connector and engine ground.

Connector & terminal

(E57) No. 6 (+) — Engine ground (

−

):

(E57) No. 4 (+) — Engine ground (

−

):

Is the voltage less than 10 V?

Go to step 21.

Repair the short
circuit of harness
between ECM
connector and
electronic throttle
control connector.

Step

Check

Yes

No