Subaru Legacy 2003 Service Manual page 4008

Step
1 CHECK SET/COAST SWITCH CIRCUIT.
1) Turn ignition switch OFF.
2) Disconnect cruise control module harness
connector.
3) Measure voltage between harness connec-
tor terminal and chassis ground when SET/
COAST switch is pressed and not pressed.
Connector & terminal
(B94) No. 10 (+) — Chassis ground ( − − − − ):
Is the measured value less than the speci-
fied value, when SET/COAST switch is not
pressed?
Does the measured value exceed the spec-
ified value, when SET/COAST switch is
pressed?
2 CHECK RESUME/ACCEL SWITCH CIRCUIT.
Measure voltage between harness connector
terminal and chassis ground when RESUME/
ACCEL switch is pressed and not pressed.
Connector & terminal
(B94) No. 9 (+) — Chassis ground ( − − − − ):
Is the measured value less than the specified
value, when RESUME/ACCEL switch is not
pressed?
Does the measured value exceed the specified
value, when RESUME/ACCEL switch is
pressed?
3 CHECK CANCEL SWITCH CIRCUIT.
Measure voltage between harness connector
terminal and chassis ground when CANCEL
switch is pressed and not pressed.
Connector & terminal
(B94) No. 9 (+) — Chassis ground ( − − − − ):
(B94) No. 10 (+) — Chassis ground ( − − − − ):
Is the measured value less than the specified
value, when CANCEL switch is not pressed?
Does the measured value exceed the specified
value, when CANCEL switch is pressed?
4 CHECK POWER SUPPLY FOR COMMAND
SWITCH.
Check horn operation.
Does horn sound?
5 CHECK CRUISE CONTROL COMMAND
SWITCH.
Remove and check cruise control command
switch. <Ref. to CC-8, Cruise Control Com-
mand Switch.>
Is cruise control command switch OK?
DIAGNOSTICS CHART WITH SYMPTOM
CRUISE CONTROL SYSTEM (DIAGNOSTICS)
Value
When SET/COAST switch is
not pressed: 0 V, and when
SET/COAST switch is
pressed: 10 V
When RESUME/ACCEL
switch is not pressed: 0 V, and
when RESUME/ACCEL switch
is pressed: 10 V
When CANCEL switch is not
pressed: 0 V, and when CAN-
CEL switch is pressed: 10 V
Horn sounds.
Cruise control command
switch is OK.
CC-19
Yes
Go to step 2. Go to step 4.
Go to step 3. Go to step 4.
Cruise control Go to step 4.
command switch
circuit is OK.
Go to step 5. • Check fuse No.
6 (in main fuse
box).
• Check horn
relay. <Ref. to
COM-3, HORN
RELAY, INSPEC-
TION, Horn Sys-
tem.>
• Check harness
for open or short
between cruise
control command
switch and fuse &
relay box.
Check harness Replace cruise
between cruise control command
control command switch.
switch and cruise
control module.
No