Subaru Legacy IV (2008 year). Service manual — part 511

EN(H6DO)(diag)-17

Engine Control Module (ECM) I/O Signal

ENGINE (DIAGNOSTICS)

5. Engine Control Module (ECM) I/O Signal

A: ELECTRICAL SPECIFICATION

Description

Connector

No.

Terminal

No.

Signal (V)

Reference

Ignition SW ON

(engine OFF)

Engine ON

(idling)

Crankshaft posi-
tion sensor

Signal (+)

B134

13

0

–7 — +7

Waveform

Signal (–)

B134

14

0

0

—

Shield

B134

24

0

0

—

Camshaft posi-
tion sensor (LH)

Signal

B134

21

0.275

0 or 5

Waveform

Ground

B134

22

0

0

—

Camshaft posi-
tion sensor (RH)

Signal

B134

11

0.275

0 or 5

Waveform

Ground

B134

22

0

0

—

Electronic throt-
tle control

Main

B134

18

0.64 — 0.94

Fully opened: 4.01

0.64 — 0.72

(After engine is

warmed up.)

Fully closed: 0.6

Fully opened: 4.01

Sub

B134

28

1.51 — 1.76

Fully opened: 4.23

1.51 — 1.58

(After engine is

warmed up.)

Fully closed: 1.48

Fully opened: 4.23

Electronic throttle control motor
(+)

B137

5

Duty waveform

Duty waveform

Drive frequency:

500 Hz

Electronic throttle control motor
(–)

B137

4

Duty waveform

Duty waveform

Drive frequency:

500 Hz

Electronic throttle control motor
power supply

B136

1

10 — 13

12 — 14

—

Electronic throttle control motor
relay

B136

21

ON: 0

OFF: 10 — 13

ON: 0

OFF: 12 — 14

When ignition switch

is turned to ON: ON

EGR valve

Signal A+

B134

8

10 — 13

12 — 14

—

Signal A–

B134

9

10 — 13

12 — 14

—

Signal B+

B134

10

10 — 13

12 — 14

—

Signal B–

B134

20

10 — 13

12 — 14

—

EN-05288

B134

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

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

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
29

30

31

32

33

34

35

B137

5

6

7

8

2

1

9

4

3

10

22

23

11

12

13

14

15

24

25

26

16

17

18

19

20

21

27

28

29

30

31

TO A:

TO B:

TO C:

TO D:

EN(H6DO)(diag)-18

Engine Control Module (ECM) I/O Signal

ENGINE (DIAGNOSTICS)

Accelerator pedal
position sensor

Main sensor
signal

B135

23

Fully closed: 1

Fully opened: 3.6

Fully closed: 1

Fully opened: 3.3

—

Main power
supply

B135

21

5

5

—

Ground
(main sensor)

B135

29

0

0

—

Sub sensor
signal

B135

31

Fully closed: 1

Fully opened: 3.7

Fully closed: 1

Fully opened: 3.3

—

Sub power
supply

B135

22

5

5

—

Ground
(sub sensor)

B135

30

0

0

—

Engine coolant temperature
sensor

B134

34

1.0 — 1.4

1.0 — 1.4

After engine is

warmed up.

Starter switch

B136

32

0

0

Cranking: 8 — 14

Starter relay

B136

20

ON: 0

OFF: 10 — 13

ON: 0

OFF: 12 — 14

—

A/C switch

B136

24

ON: 10 — 13

OFF: 0

ON: 12 — 14

OFF: 0

—

A/C lock sensor

B135

14

Duty waveform

Duty waveform

Auto A/C model

A/C middle pressure switch

B136

33

ON: 0

OFF: 10 — 13

ON: 0

OFF: 12 — 14

—

Ignition switch

B135

19

10 — 13

12 — 14

—

Neutral position switch

B136

31

ON: 0

OFF: 12

r0.5

Switch is ON when

select lever is shifted

into “P” range or “N”

range.

Delivery (test) mode connector

B135

27

12 — 14

12 — 14

When connected: 0

Knock sensor 1

Signal

B134

15

2.4

2.4

—

Shield

B134

25

0

0

—

Knock sensor 2

Signal

B134

16

2.4

2.4

—

Shield

B134

25

0

0

—

Back-up power supply

B135

5

10 — 13

12 — 14

Ignition switch “OFF”:

10 — 13

Control module power supply

B135

2

10 — 13

12 — 14

—

B134

7

10 — 13

12 — 14

—

Sensor power supply

B134

19

5

5

—

Ignition control

#1

B137

18

0

0 — 14

Waveform

#2

B137

19

0

0 — 14

Waveform

#3

B137

20

0

0 — 14

Waveform

#4

B137

21

0

0 — 14

Waveform

#5

B137

22

0

0 — 14

Waveform

#6

B137

23

0

0 — 14

Waveform

Fuel injector

#1

B137

8

10 — 13

1 — 14

Waveform

#2

B137

9

10 — 13

1 — 14

Waveform

#3

B137

10

10 — 13

1 — 14

Waveform

#4

B137

11

10 — 13

1 — 14

Waveform

#5

B137

12

10 — 13

1 — 14

Waveform

#6

B137

13

10 — 13

1 — 14

Waveform

A/C relay control

B136

9

ON: 0.5 or less

OFF: 10 — 13

ON: 0.5 or less

OFF: 12 — 14

—

Description

Connector

No.

Terminal

No.

Signal (V)

Reference

Ignition SW ON

(engine OFF)

Engine ON

(idling)

EN(H6DO)(diag)-19

Engine Control Module (ECM) I/O Signal

ENGINE (DIAGNOSTICS)

Blower fan switch

B135

16

ON: 0

OFF: 10 — 13

ON: 0

OFF: 12 — 14

Manual A/C model

Radiator fan control

B136

18

ON: 0.5 or less

OFF: 10 — 13

ON: 0.5 or less

OFF: 12 — 14

—

Radiator fan control power supply

B136

29

ON: 0.5 or less

OFF: 10 — 13

ON: 0.5 or less

OFF: 12 — 14

—

Self-shutoff control

B136

23

0

0

—

Malfunction indicator light

B136

11

—

—

Light “ON”: 1 or less

Light “OFF”: 10 — 14

Engine speed output

B136

22

—

0 — 13 or more

Waveform

Purge control solenoid valve

B137

29

ON: 1 or less

OFF: 10 — 13

ON: 1 or less

OFF: 12 — 14

—

Power steering switch

B134

33

ON: 1 or less

OFF: 10 — 13

ON: 1 or less

OFF: 12 — 14

—

Manifold absolute pressure sensor

B134

6

3.5 — 4.8

1.1 — 1.9

—

Air flow sensor

Signal

B135

26

0.74

0.3 — 4.5

—

Shield

B135

35

0

0

—

Ground

B135

34

0

0

—

Intake air temperature sensor

B135

18

3.15 — 3.33

3.15 — 3.33

Intake air temperature:

25°C (77°F)

Front oxygen (A/F)
sensor RH

Signal (+)

B135

9

2.8 — 3.2

2.8 — 3.2

—

Signal (–)

B135

8

2.4 — 2.7

2.4 — 2.7

—

Shield

B135

1

0

0

—

Front oxygen (A/F)
sensor heater RH

Signal 1

B136

3

12 — 14

—

Waveform

Signal 2

B136

2

12 — 14

—

Waveform

Front oxygen (A/F)
sensor LH

Signal (+)

B135

11

2.8 — 3.2

2.8 — 3.2

—

Signal (–)

B135

10

2.4 — 2.7

2.4 — 2.7

—

Shield

B135

1

0

0

—

Front oxygen (A/F)
sensor heater LH

Signal 1

B135

7

12 — 14

—

Waveform

Signal 2

B135

6

12 — 14

—

Waveform

Rear oxygen
sensor RH

Signal

B135

4

0

0 — 0.9

—

Shield

B135

1

0

0

—

Rear oxygen sensor heater RH
signal

B136

4

12 — 14

—

Waveform

Rear oxygen
sensor LH

Signal

B135

15

0

0 — 0.9

—

Shield

B135

1

0

0

—

Rear oxygen sensor heater LH
signal

B136

5

12 — 14

—

Waveform

Immobilizer communication 1

B136

26

10

10

—

Immobilizer communication 2

B136

34

10

10

—

Fuel pump con-
trol unit

Signal 1

B135

33

0

12 — 14

—

Signal 2

B136

12

0

0 or 5

—

Brake switch 1

B135

20

When brake pedal is

depressed: 0

When brake pedal is

released: 10 — 13

When brake pedal is

depressed: 0

When brake pedal is

released: 12 — 14

—

Brake switch 2

B135

28

When brake pedal is

depressed: 10 — 13

When brake pedal is

released: 0

When brake pedal is

depressed: 12 — 14

When brake pedal is

released: 0

—

Description

Connector

No.

Terminal

No.

Signal (V)

Reference

Ignition SW ON

(engine OFF)

Engine ON

(idling)

EN(H6DO)(diag)-20

Engine Control Module (ECM) I/O Signal

ENGINE (DIAGNOSTICS)

Cruise control command switch

B135

24

When not operating:

3.5 — 4.5

When operating

RES/ACC: 2.5 — 3.5

When operating SET/

COAST: 0.5 — 1.5

When operating

CANCEL: 0 — 0.5

When not operating:

3.5 — 4.5

When operating

RES/ACC: 2.5 — 3.5

When operating SET/

COAST: 0.5 — 1.5

When operating

CANCEL: 0 — 0.5

—

Cruise control main switch

B135

12

ON: 0

OFF: 5

ON: 0

OFF: 5

—

Oil flow control
solenoid valve RH

Signal (+)

B137

17

0

0.6

—

Signal (–)

B137

16

0

0

—

Oil flow control
solenoid valve LH

Signal (+)

B137

15

0

0.6

—

Signal (–)

B137

14

0

0

—

Oil switching
solenoid valve RH

Signal (+)

B137

25

0

1.9

—

Signal (–)

B137

24

0

0

—

Oil switching
solenoid valve LH

Signal (+)

B137

31

0

1.9

—

Signal (–)

B137

30

0

0

—

Oil temperature sensor signal

B134

23

1.0 — 1.4

1.0 — 1.4

After engine is

warmed up.

Variable valve lift diagnosis oil
pressure switch RH

B134

31

0

0

—

Variable valve lift diagnosis oil
pressure switch LH

B134

32

0

0

—

Generator control

B136

10

0 — 6.5

0 — 6.5

—

SSM communication line

B136

16

1 or less

mo 4 or

more

1 or less

mo 4 or

more

—

Clutch switch

B136

25

10 — 13

12 — 14

—

GND (sensor)

B135

30

0

0

—

Ground (ignition
system)

(Ignition 1)

B137

26

0

0

—

(Ignition 2)

B137

6

0

0

—

Ground

Engine 1

B134

5

0

0

—

Engine 2

B137

7

0

0

—

Engine 3

B137

2

0

0

—

Engine 4

B137

1

0

0

—

Engine 5

B137

3

0

0

—

Engine 6

B134

3

0

0

—

Body

B136

6

0

0

—

Sensor GND (engine side)

B134

29

0

0

—

Fuel tank pressure sensor

B135

32

2.3

2.7

—

Pressure control solenoid valve

B136

28

ON: 1 or less

OFF: 10 — 13

ON: 1 or less

OFF: 12 — 14

—

Drain valve

B136

17

ON: 1 or less

OFF: 10 — 13

ON: 1 or less

OFF: 12 — 14

—

Fuel temperature sensor

B135

17

2.5 — 3.8

2.5 — 3.8

Ambient tempera-

ture: 25°C (77°F)

CAN communication (+)

B136

27

2.0 — 4.5

2.0 — 4.5

Waveform

CAN communication (–)

B136

35

0.5 — 3.0

0.5 — 3.0

Waveform

Description

Connector

No.

Terminal

No.

Signal (V)

Reference

Ignition SW ON

(engine OFF)

Engine ON

(idling)