Subaru Legacy IV (2008 year). Manual — part 1158

CC(diag)-14

Diagnostic Procedure with Cancel Code

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK CRUISE CONTROL COMMAND
SWITCH CIRCUIT.
1) Remove the driver’s airbag module. <Ref. to
AB-14, REMOVAL, Driver’s Airbag Module.>
2) Disconnect the harness connector of cruise
control command switch.
3) Turn the ignition switch to ON.
4) Measure the voltage between harness con-
nector terminal and chassis ground.

Connector & terminal

(ST3) No. 8 (+) — Chassis ground (–):
(ST3) No. 7 (+) — Chassis ground (–):

Is the voltage 5 V or more?

Go to step 2.

Check for open,
shorted circuit, or
poor contact of
harness between
cruise control com-
mand switch and
ECM and steering
roll connector.

2

CHECK CRUISE CONTROL COMMAND
SWITCH CIRCUIT.
1) Turn the ignition switch to OFF.
2) Remove the cruise control command
switch. <Ref. to CC-5, REMOVAL, Cruise Con-
trol Command Switch.>
3) Measure the resistance between harness
connector terminal and chassis ground.

Connector terminal

(ST3) No. 6 — Chassis ground:

Is the resistance less than 10

:? Go to step 3.

Check for open
between cruise
control command
switch and ECM
and chassis
ground, and check
the ECM.

3

CHECK CRUISE CONTROL COMMAND
SWITCH.
Measure the resistance between switch termi-
nals when the cruise control command switch is
not depressed.

Terminals

No. 6 — No. 7:

Is the resistance approx. 4 k

:? Go to step 4.

Replace the cruise
control command
switch.
<Ref. to CC-5,
Cruise Control
Command
Switch.>

4

CHECK CANCEL SWITCH.
1) Turn the ignition switch to OFF.
2) Remove the cruise control command
switch. <Ref. to CC-5, REMOVAL, Cruise Con-
trol Command Switch.>
3) Measure the resistance between switch ter-
minals with the CANCEL switch pressed.

Terminals

No. 6 — No. 7:

Is the resistance approx. less
than 1

: when the CANCEL

switch is pressed?

Go to step 5.

Replace the cruise
control command
switch.
<Ref. to CC-5,
Cruise Control
Command
Switch.>

5

CHECK SET/COAST SWITCH.
Measure the resistance between switch termi-
nals with the SET/COAST switch pressed.

Terminals

No. 6 — No. 7:

Is the resistance approx. 250

:

when SET/COAST switch is
pressed?

Go to step 6.

Replace the cruise
control command
switch. <Ref. to
CC-5, Cruise Con-
trol Command
Switch.>

6

CHECK RESUME/ACCEL SWITCH CIRCUIT.
Measure the resistance between switch termi-
nals when the RESUME/ACCEL switch is
pressed.

Terminals

No. 6 — No. 7:

Is the resistance approx. 1,500

:

when RESUME/ACCEL switch
is pressed?

Replace the ECM.
<Ref. to
FU(H4SO)-39,
Engine Control
Module (ECM).>
<Ref. to
FU(H4DOTC)-52,
Engine Control
Module (ECM).>
<Ref. to
FU(H6DO)-38,
Engine Control
Module (ECM).>

Replace the cruise
control command
switch. <Ref. to
CC-5, Cruise Con-
trol Command
Switch.>

CC(diag)-15

Diagnostic Procedure with Cancel Code

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

B: 12

The DTC is detected when the brake pedal is pressed or problem relating to stop light & brake switch occurs.
TROUBLE SYMPTOM:
• Cruise control cannot be set.
• Cruise control cannot be released.
WIRING DIAGRAM:

MAIN SBF

SBF-2

SBF-8

F/B No. 8

F/B No. 4

B65

4

3

1

2

B65

1

2

3

4

B28

B20

C25

B135

B:

B136

C:

ECM

B136

9

30

29

2

3

8

2

31

20

19

18

22

21

10

12

11

14

24

34

33

27

26

16

1

2

3

4

5

6

13

23

15

25

8

7

17

35

C:

5

B159

9

9

4

7

6

2

1
5

3
8

B159

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

B:

B225

AT

: AT MODEL

MT

: MT MODEL

4

3

B225

CC-00684

2

1

B107

AT

AT

MT

13
14

15 16

17

27

24

25
26

20

21
22

23

29
30

31

28

32

35

33
34

37
38

39

36

40

8

9

10

11 12

1

2

5

3

4

7

6

19

18

B107

1 2

7.5A

FUSE & RELAY BOX

MT

BATTERY

IGNITION

RELAY

RELAY BOX

RELAY BLOCK

CLUTCK SWITCH (MT)

STOP LIGHT SWITCH
AND BRAKE SWITCH

STOP LIGHT

SWITCH

BRAKE

SWITCH

CC(diag)-16

Diagnostic Procedure with Cancel Code

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK STOP LIGHT & BRAKE SWITCH
CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the stop light & brake switch har-
ness connector.
3) Turn the ignition switch to ON.
4) Measure the voltage between harness con-
nector terminal and chassis ground.

Connector & terminal

(B65) No. 2 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step 2.

• Check fuse No. 8
(in fuse & relay
box).
• Check for open
or short circuit in
the harness
between stop light
& brake switch and
fuse & relay box.

2

CHECK STOP LIGHT & BRAKE SWITCH
CIRCUIT.
Measure the voltage between harness connec-
tor terminal and chassis ground.

Connector & terminal

(B65) No. 4 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step 3.

• Check fuse No. 4
(in fuse & relay
box).
• Check for open
or short in the har-
ness between stop
light & brake switch
and fuse & relay
box.

3

CHECK STOP LIGHT & BRAKE SWITCH
CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the harness connector of ECM.
3) Measure the resistance between ECM har-
ness connector terminal and stop light & brake
switch harness connector terminal.

Connector & terminal

(B135) No. 28 — (B65) No. 3:
(B135) No. 20 — (B65) No. 1:

Is the resistance less than 10

:? Go to step 4.

Repair the har-
ness.

4

CHECK STOP LIGHT & BRAKE SWITCH
CIRCUIT.
Remove and check the stop light & brake
switch. <Ref. to CC-7, Stop Light & Brake
Switch.>

Is the stop light & brake switch
OK?

Replace the ECM.
<Ref. to
FU(H4SO)-39,
Engine Control
Module (ECM).>
<Ref. to
FU(H4DOTC)-52,
Engine Control
Module (ECM).>
<Ref. to
FU(H6DO)-38,
Engine Control
Module (ECM).>

Replace the stop
light & brake
switch.

CC(diag)-17

Diagnostic Procedure with Cancel Code

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

C: 13

The DTC is detected when the clutch pedal is depressed or problem relating to the clutch switch occurs.
TROUBLE SYMPTOM:
• Cruise control cannot be set.
• Cruise control cannot be released.
WIRING DIAGRAM:

MAIN SBF

SBF-2

SBF-8

F/B No. 8

F/B No. 4

B65

4

3

1

2

B65

1

2

3

4

B28

B20

C25

B135

B:

B136

C:

ECM

B136

9

30

29

2

3

8

2

31

20

19

18

22

21

10

12

11

14

24

34

33

27

26

16

1

2

3

4

5

6

13

23

15

25

8

7

17

35

C:

5

B159

9

9

4

7

6

2

1
5

3
8

B159

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

B:

B225

AT

: AT MODEL

MT

: MT MODEL

4

3

B225

CC-00684

2

1

B107

AT

AT

MT

13
14

15 16

17

27

24

25
26

20

21
22

23

29
30

31

28

32

35

33
34

37
38

39

36

40

8

9

10

11 12

1

2

5

3

4

7

6

19

18

B107

1 2

7.5A

FUSE & RELAY BOX

MT

BATTERY

IGNITION

RELAY

RELAY BOX

RELAY BLOCK

CLUTCK SWITCH (MT)

STOP LIGHT SWITCH
AND BRAKE SWITCH

STOP LIGHT

SWITCH

BRAKE

SWITCH