Subaru Legacy III (2000-2003 year). Service manual — part 1000

CC-20

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SYMPTOM

E: CHECK STOP LIGHT SWITCH AND BRAKE SWITCH

TROUBLE SYMPTOM:
Cruise control cannot be set.
WIRING DIAGRAM:

CC-00080

CRUISE

CONTROL

MODULE

B65

BRAKE

SWITCH

STOP LIGHT

SWITCH

STOP LIGHT SWITCH
AND BRAKE SWITCH

CLUTCH
SWITCH (MT)

2

1

4
3

BATTERY

F/B NO. 16

SBF-1

SBF-2

1
2

MT

MT

AT

AT

B94

B107

16

11

20

B65

1 2
3 4

B107

1 2

B94

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

CC-21

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SYMPTOM

Step

Value

Yes

No

1

CHECK STOP LIGHT SWITCH AND BRAKE
SWITCH CIRCUIT.
1) Turn ignition switch OFF.
2) Disconnect stop light switch and brake

switch harness connector.

3) Turn ignition switch ON.
4) Turn cruise control main switch ON.
5) Measure voltage between harness connec-

tor terminal and chassis ground.

Connector & terminal

(B65) No. 2 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Go to step 2.

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

2

CHECK STOP LIGHT SWITCH AND BRAKE
SWITCH CIRCUIT.
Measure voltage between harness connector
terminal and chassis ground.

Connector & terminal

(B65) No. 1 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the specified
value?

10 V

Go to step 3.

• Check harness
for open or short
between stop light/
brake switch and
cruise control
module (AT).
• Check clutch
switch and the cir-
cuit (MT).

3

CHECK STOP LIGHT SWITCH AND BRAKE
SWITCH CIRCUIT.
1) Turn cruise control main switch and ignition

switch OFF.

2) Disconnect cruise control module harness

connector.

3) Measure resistance between cruise control

module harness connector terminal and
stop light switch and brake switch harness
connector terminal.

Connector & terminal

(B94) No. 20 — (B65) No. 3:
(B94) No. 16 — (B65) No. 4:

Is the measured value less than the speci-
fied value?

10

Ω

Go to step 4.

Repair harness.

4

CHECK STOP LIGHT SWITCH AND BRAKE
SWITCH.
Remove and check stop light switch and brake
switch. <Ref. to CC-9, Stop and Brake
Switch.>
Are stop light switch and brake switch OK?

Stop light switch and brake
switch are OK.

Stop light switch
and brake switch
circuit are OK.

Replace stop light
switch and brake
switch.

CC-22

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SYMPTOM

F: CHECK CLUTCH SWITCH (MT)

TROUBLE SYMPTOM:
Cruise control cannot be set.
WIRING DIAGRAM:

CC-00080

CRUISE

CONTROL

MODULE

B65

BRAKE

SWITCH

STOP LIGHT

SWITCH

STOP LIGHT SWITCH
AND BRAKE SWITCH

CLUTCH
SWITCH (MT)

2

1

4
3

BATTERY

F/B NO. 16

SBF-1

SBF-2

1
2

MT

MT

AT

AT

B94

B107

16

11

20

B65

1 2
3 4

B107

1 2

B94

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

CC-23

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SYMPTOM

Step

Value

Yes

No

1

CHECK CLUTCH SWITCH CIRCUIT.
1) Turn ignition switch OFF.
2) Disconnect clutch switch harness connec-

tor.

3) Turn ignition switch ON.
4) Turn cruise control main switch ON.
5) Measure voltage between harness connec-

tor terminal and chassis ground.

Connector & terminal

(B107) No. 2 (+) — Chassis ground (

−−−−

):

Does the measured value exceed the spec-
ified value?

10 V

Go to step 2.

Check harness for
open or short
between clutch
switch and cruise
control module.

2

CHECK CLUTCH SWITCH CIRCUIT.
1) Turn cruise control main switch and ignition

switch OFF.

2) Disconnect stop light switch and brake

switch harness connector.

3) Measure resistance between clutch switch

harness connector terminal and stop light
switch and brake switch harness connector
terminal.

Connector & terminal

(B107) No. 1 — (B65) No. 1:

Is the measured value less than the speci-
fied value?

10

Ω

Go to step 3.

Repair harness.

3

CHECK CLUTCH SWITCH.
Remove and check clutch switch. <Ref. to CC-
10, Clutch Switch.>
Is clutch switch OK?

Clutch switch is OK.

Clutch switch cir-
cuit is OK.

Replace clutch
switch.