Subaru Legacy IV (2008 year). Service manual — part 1155

CC(diag)-2

Basic Diagnostic Procedure

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

1. Basic Diagnostic Procedure

A: PROCEDURE

Step

Check

Yes

No

1

CHECK MALFUNCTION INDICATOR LIGHT.
Make sure the malfunction indicator light illumi-
nates.

Does the malfunction indicator
light illuminate?

Go to step 5.

Go to step 2.

2

CHECK CRUISE INDICATOR LIGHT.
Make sure the cruise indicator light blinks.

Does the cruise indicator light
blink?

Go to step 5.

Go to step 3.

3

CHECK CRUISE CONTROL MAIN SWITCH
OPERATION.
Check cruise control main switch operation.
(Ensure the cruise indicator light illuminates.)

Is the cruise control main switch
turned on? (Does the cruise
indicator light illuminate?)

Go to step 4.

Go to phenome-
non 1. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

4

CHECK CRUISE CONTROL SET OPERA-
TION.
Check the cruise control setting operation.

Can the cruise control be set
while driving at 40 km/h (25 MPH)
or more?

Go to step 7.

Go to step 6.

5

CHECK DTC.
Read all DTCs using the Subaru Select Monitor.

Is an engine or ABS/VDC
related DTC displayed?

Perform the diag-
nosis according to
DTC.

Go to phenome-
non 2. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

6

CHECK CANCEL CODE.
Using the Subaru Select Monitor, read the can-
cel codes.

NOTE:
• Do not turn the ignition switch to OFF after the
cruise control is deactivated.
• Do not operate the cruise control command
switch after the cruise control is deactivated.
If the above is performed, the cancel code will
be cleared.

Is it possible to read the cancel
codes?

Perform the diag-
nosis according to
the cancel code.
<Ref. to CC(diag)-
11, LIST, List of
Cancel Code.>

Go to step 7.

7

CHECK CRUISE SET INDICATOR LIGHT.
Make sure the cruise set indicator light illumi-
nates.

Does the cruise set indicator
light illuminate?

Go to step 8.

Go to phenome-
non 3. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

8

CHECK VEHICLE SPEED IS HELD WITHIN
SET SPEED.
Make sure the vehicle speed is held within set
speed.

Is the vehicle speed kept within
setting speed

r3 km/h (r2 MPH)?

(Make sure that on a level
road.)

Go to step 9.

Go to phenome-
non 4. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

CC(diag)-3

Basic Diagnostic Procedure

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

9

CHECK RESUME/ACCEL OPERATION.
Check the RESUME/ACCEL switch operation.

Does the vehicle speed
increase or return to set speed
after RESUME/ACCEL switch
has been pressed?

Go to step 10.

Go to phenome-
non 5. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

10

CHECK SET/COAST OPERATION.
Check the SET/COAST switch operation.

Does the vehicle speed
decrease after SET/COAST
switch has been pressed?

Go to step 11.

Go to phenome-
non 6. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

11

CHECK CANCEL OPERATION.
Check the CANCEL switch operation.

Is the cruise control released
after CANCEL switch has been
pressed?

Go to step 12.

Go to phenome-
non 7. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

12

CHECK CRUISE CONTROL RELEASE OP-
ERATION.
Check the cruise control release operation.

Is the cruise control released
after brake pedal has been
depressed?

Go to step 13.

Go to phenome-
non 8. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

13

CHECK CRUISE CONTROL RELEASE OP-
ERATION.
Check the cruise control release operation.

Is the cruise control released
after shifting to the neutral posi-
tion?

Go to step 14.

Go to phenome-
non 9. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

14

CHECK CRUISE CONTROL RELEASE OP-
ERATION.
Check the cruise control release operation.

Is the cruise control released
after depressing the clutch
pedal?

Finish the diagno-
sis.

Go to phenome-
non 10. <Ref. to
CC(diag)-9, DIAG-
NOSTIC PROCE-
DURE WITH
PHENOMENON,
Diagnostics with
Phenomenon.>

Step

Check

Yes

No

CC(diag)-4

General Description

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

2. General Description

A: CAUTION

Airbag system wiring harness is routed near the cruise control command switch.

CAUTION:
• Airbag system wiring harnesses and connectors are yellow. Do not use electrical test equipment
on these circuits.
• Be careful not to damage the airbag system wiring harness when servicing the cruise control com-
mand switch. Airbag system wiring harness is routed near the cruise control command switch.

B: PREPARATION TOOL

1. SPECIAL TOOL

2. GENERAL TOOL

C: INSPECTION

Measure the battery voltage and specific gravity of electrolyte.

Standard voltage:

12 V or more

Specific gravity:

1.260 or more

ILLUSTRATION

TOOL NUMBER

DESCRIPTION

REMARKS

1B022XU0

SUBARU SELECT
MONITOR III KIT

Used for troubleshooting the electrical system.

TOOL NAME

REMARKS

Circuit tester

Used for measuring resistance, voltage and current.

ST1B022XU0

CC(diag)-5

Electrical Component Location

CRUISE CONTROL SYSTEM (DIAGNOSTICS)

3. Electrical Component Location

A: LOCATION

(1)

Engine control module (ECM)

(5)

Transmission control module
(TCM) (AT model)

(7)

Neutral position switch (MT
model)

(2)

Cruise control command switch

(3)

Stop light & brake switch

(6)

Inhibitor switch (AT model)

(8)

Clutch switch (MT model)

(4)

Cruise indicator light and cruise
set indicator light

CC-00687

(7)

(1)

(4)

(2)

(3)

(8)

(5)

(6)