Subaru Legacy (2005 year). Service manual — part 426

EN(H6DO)(diag)-17

ENGINE (DIAGNOSTICS)

Engine Control Module (ECM) I/O Signal

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

A: ELECTRICAL SPECIFICATION

Description

Connector

No.

Termi-

nal

No.

Signal (V)

Reference

Ignition SW ON

(engine OFF)

Engine ON

(idling)

Crankshaft
position sen-
sor

Signal (+)

B135

10

0

−7 — +7

Waveform

Signal (

−)

B135

22

0

0

—

Shield

B135

31

0

0

—

Camshaft position sensor
(LH)

B135

8

0.275

0 or 5

Waveform

Camshaft position sensor
(RH)

B135

9

0.275

0 or 5

Waveform

Electronic
throttle control

Main

B136

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

B136

29

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

B137

6

10 — 13

12 — 14

—

Electronic throttle control
motor relay

B135

35

ON: 0

OFF: 10 — 13

ON: 0

OFF: 13 — 14

When ignition switch is

turned to ON: ON

Accelerator
pedal position
sensor

Main

B136

17

Fully closed: 1

Fully opened: 3.6

Fully closed: 1

Fully opened: 3.3

—

Power
supply

B136

15

5

5

—

Ground

B136

34

0

0

—

Sub

B136

28

Fully closed: 1

Fully opened: 3.7

Fully closed: 1

Fully opened: 3.3

—

Engine coolant temperature
sensor

B136

14

1.0 — 1.4

1.0 — 1.4

After engine is warmed-up.

Starter switch

B137

8

0

0

Cranking: 8 — 14

EN-01812

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

To

To

To

EN(H6DO)(diag)-18

ENGINE (DIAGNOSTICS)

Engine Control Module (ECM) I/O Signal

Starter relay

B135

32

ON: 0

OFF: 10 — 13

ON: 0

OFF: 13 — 14

—

A/C switch

B137

17

ON: 10 — 13

OFF: 0

ON: 13 — 14

OFF: 0

—

Ignition switch

B137

14

10 — 13

13 — 14

—

Neutral position switch

B137

9

ON: 0

OFF: 12

±0.5

• Switch is ON when
shifted into “P” or “N”
range. (AT model)
• Switch is ON when
shifted into “N” range. (MT
model)

Test mode connector

B137

15

12 — 14

12 — 14

When connected: 0

Knock sensor
1

Signal

B136

25

2.4

2.4

—

Shield

B136

33

0

0

—

Knock sensor
2

Signal

B136

24

2.4

2.4

—

Shield

B136

33

0

0

—

Backup power supply

B135

19

10 — 13

13 — 14

Ignition switch “OFF”:

10 — 13

Control module power sup-
ply

B135

6

10 — 13

13 — 14

—

B135

5

10 — 13

13 — 14

—

Sensor power supply

B136

16

5

5

—

Ignition control

#1

B135

18

0

13 — 14

Waveform

#2

B135

17

0

13 — 14

Waveform

#3

B135

16

0

13 — 14

Waveform

#4

B135

15

0

13 — 14

Waveform

#5

B135

14

0

13 — 14

Waveform

#6

B135

13

0

13 — 14

Waveform

Fuel injector

#1

B136

6

10 — 13

1 — 14

Waveform

#2

B136

5

10 — 13

1 — 14

Waveform

#3

B136

4

10 — 13

1 — 14

Waveform

#4

B136

3

10 — 13

1 — 14

Waveform

#5

B136

2

10 — 13

1 — 14

Waveform

#6

B136

1

10 — 13

1 — 14

Waveform

A/C relay control

B135

33

ON: 0.5 or less

OFF: 10 — 13

ON: 0.5 or less

OFF: 13 — 14

—

Radiator fan control

B134

31

ON: 0.5 or less

OFF: 10 — 13

ON: 0.5 or less

OFF: 13 — 14

—

Radiator fan control power
supply

B135

30

ON: 0.5 or less

OFF: 10 — 13

ON: 0.5 or less

OFF: 13 — 14

—

Self shut-off control

B137

16

0

0

—

Malfunction indicator light

B134

17

—

—

Light ON: 1 or less

Light OFF: 10 — 14

Engine speed output

B134

23

—

0 — 13 or more

Waveform

Purge control solenoid valve

B134

14

ON: 1 or less

OFF: 10 — 13

ON: 1 or less

OFF: 13 — 14

—

EGR solenoid
valve

Signal A+

B134

11

10 — 13

10 — 13

—

Signal A

−

B134

10

10 — 13

10 — 13

—

Signal B+

B134

9

10 — 13

10 — 13

—

Signal B

−

B134

8

10 — 13

10 — 13

—

Power steering switch

B137

10

ON: 1 or less

OFF: 10 — 13

ON: 1 or less

OFF: 13 — 14

—

Description

Connector

No.

Termi-

nal

No.

Signal (V)

Reference

Ignition SW ON

(engine OFF)

Engine ON

(idling)

EN(H6DO)(diag)-19

ENGINE (DIAGNOSTICS)

Engine Control Module (ECM) I/O Signal

A/C middle pressure switch

B136

30

ON: 0

OFF: 10 — 13

ON: 0

OFF: 13 — 14

—

Manifold absolute pressure
sensor

B136

22

3.5 — 4.8

1.1 — 1.9

—

Air flow sensor

Signal

B136

23

0.74

0.3 — 4.5

—

Shield

B136

32

0

0

—

Ground

B136

31

0

0

—

Intake air temperature sen-
sor

B136

13

3.15 — 3.33

3.15 — 3.33

intake air temperature:

25

°C (75°F)

Front oxygen
(A/F) sensor
RH

Signal (+)

B134

33

2.8 — 3.2

2.8 — 3.2

—

Signal (

−)

B134

26

2.4 — 2.7

2.4 — 2.7

—

Shield

B134

25

0

0

—

Front oxygen
(A/F) sensor
heater RH

Signal 1

B134

3

12 — 14

—

Waveform

Signal 2

B134

2

12 — 14

—

Waveform

Front oxygen
(A/F) sensor
LH

Signal (+)

B134

34

2.8 — 3.2

2.8 — 3.2

—

Signal (

−)

B134

27

2.4 — 2.7

2.4 — 2.7

—

Shield

B134

25

0

0

—

Front oxygen
(A/F) sensor
heater LH

Signal 1

B134

1

12 — 14

—

Waveform

Signal 2

B135

7

12 — 14

—

Waveform

Rear oxygen
sensor RH

Signal

B137

24

0

0 — 0.9

—

Shield

B137

31

0

0

—

Rear oxygen sensor heater
RH signal

B135

2

12 — 14

—

Waveform

Rear oxygen
sensor LH

Signal

B137

25

0

0 — 0.9

—

Shield

B137

31

0

0

—

Rear oxygen sensor heater
LH signal

B135

3

12 — 14

—

Waveform

Immobilizer communication
1

B137

19

10

10

—

Immobilizer communication
2

B137

27

10

10

—

Fuel pump
control unit

Signal 1

B137

28

0

13 — 14

—

Signal 2

B135

27

0

0 or 5

—

Brake switch 1

B136

9

When brake pedal is

depressed: 0

When brake pedal is

released: 10 — 13

When brake pedal is

depressed: 0

When brake pedal is

released: 13 — 14

—

Brake switch 2

B136

8

When brake pedal is

depressed: 10 — 13

When brake pedal is

released: 0

When brake pedal is

depressed: 13 — 14

When brake pedal is

released: 0

—

Cruise control command
switch

B136

11

When operating noth-

ing: 3.5 — 4.5

When operating RES/

ACC: 2.5 — 3.5

When operating SET/

COAST: 0.5 — 1.5

When operating CAN-

CEL: 0 — 0.5

When operating

nothing: 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

—

Description

Connector

No.

Termi-

nal

No.

Signal (V)

Reference

Ignition SW ON

(engine OFF)

Engine ON

(idling)

EN(H6DO)(diag)-20

ENGINE (DIAGNOSTICS)

Engine Control Module (ECM) I/O Signal

Cruise control main switch

B136

7

ON: 0

OFF: 5

ON: 0

OFF: 5

—

Cruise control clutch switch

B136

10

When clutch pedal is depressed: 0

When clutch pedal is released: 12

MT model

Oil flow con-
trol solenoid
valve RH

Signal (+)

B134

18

0

0.6

—

Signal (

−)

B134

28

0

0

—

Oil flow con-
trol solenoid
valve LH

Signal (+)

B134

19

0

0.6

—

Signal (

−)

B134

29

0

0

—

Oil switching
solenoid valve
RH

Signal (+)

B134

21

0

1.9

—

Signal (

−)

B134

20

0

0

—

Oil switching
solenoid valve
LH

Signal (+)

B135

25

0

1.9

—

Signal (

−)

B135

24

0

0

—

Oil temperature sensor sig-
nal

B136

27

1.0 — 1.4

1.0 — 1.4

After engine is warmed-up.

Variable valve lift diagnosis
oil pressure switch RH

B135

21

0

0

—

Variable valve lift diagnosis
oil pressure switch LH

B135

29

0

0

—

Generator control

B134

22

0 — 6.5

0 — 6.5

—

SSM communication line

B137

20

Less than 1

←→ More

than 4

Less than 1

←→

More than 4

—

GND (sensor)

B136

35

0

0

—

GND (injector)

B137

7

0

0

—

GND (ignition system)

B135

12

0

0

—

GND (power supply)

B135

4

0

0

—

B135

1

0

0

—

GND (control system)

B137

2

0

0

—

B137

1

0

0

—

GND (Front oxygen (A/F)
sensor heater RH)

B134

7

0

0

—

GND (Front oxygen (A/F)
sensor heater LH)

B134

5

0

0

—

GND (Rear oxygen sensor
heater RH)

B134

6

0

0

—

GND (Rear oxygen sensor
heater LH)

B134

4

0

0

—

GND (Electronic throttle
control)

B137

3

0

0

—

Description

Connector

No.

Termi-

nal

No.

Signal (V)

Reference

Ignition SW ON

(engine OFF)

Engine ON

(idling)