Subaru Legacy IV (2008 year). Manual — part 914

ABS(diag)-55

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ABS (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK OUTPUT OF STOP LIGHT SWITCH
USING SUBARU SELECT MONITOR.
1) Select {Current Data Display & Save} in the
Subaru Select Monitor.
2) Release the brake pedal.
3) Read the stop light switch signal in Subaru
Select Monitor.

Is “OFF” displayed on the
screen?

Go to step 2.

Go to step 3.

2

CHECK OUTPUT OF STOP LIGHT SWITCH
USING SUBARU SELECT MONITOR.
1) Depress the brake pedal.
2) Read the stop light switch output in Subaru
Select Monitor.

Is “ON” displayed on the
screen?

Go to step 6.

Go to step 3.

3

CHECK IF STOP LIGHTS ILLUMINATE.
Depress the brake pedal.

Does the stop light illuminate?

Go to step 4.

Repair the stop
light circuit.

4

CHECK FUSE.
Check the relay block fuse (B225).

Is the fuse OK?

Go to step 5.

Replace the fuse.

5

CHECK OPEN CIRCUIT IN HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect the ABSCM&H/U connectors.
3) Depress the brake pedal.
4) Measure the voltage between ABSCM&H/U
connector and chassis ground.

Connector & terminal

(B301) No. 20 (+) — Chassis ground (–):

Is the voltage 10 — 15 V?

Go to step 6.

Repair the harness
between stop light
switch and
ABSCM&H/U con-
nector.

6

CHECK POOR CONTACT IN CONNECTOR.

Is there poor contact in the con-
nector between stop light
switch and ABSCM&H/U?

Repair the connec-
tor.

Go to step 7.

7

CHECK ABSCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to ABS(diag)-20,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
ABS(diag)-19, Inspection Mode.>
4) Read the DTC.

Is the same DTC displayed?

Replace the
ABSCM only. <Ref.
to ABS-8,
REPLACEMENT,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>

Go to step 8.

8

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
ABS(diag)-29, List
of Diagnostic Trou-
ble Code (DTC).>

Temporary poor
contact occurs.

ABS(diag)-56

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ABS (DIAGNOSTICS)

X: DTC C0118 G SENSOR OUTPUT VOLTAGE MALFUNCTION

DTC DETECTING CONDITION:
Defective G sensor
TROUBLE SYMPTOM:
ABS does not operate.
WIRING DIAGRAM:

ABS00808

ABSCM & H/U

B301

B301

10

24

21

15

B292

ABS G SENSOR

E

3

2

1

B292

1 2 3

1 2 3 4 5 6 7 8 9 10 11

16 17 18 19 20 21 22 23 24 25 26

13

12

15

14

ABS(diag)-57

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ABS (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK OUTPUT OF G SENSOR USING
SUBARU SELECT MONITOR.
1) Select {Current Data Display & Save} in the
Subaru Select Monitor.
2) Read the G sensor output on Subaru Select
Monitor.

Is the reading indicated on dis-
play –1.2 — 1.2 m/s when the G
sensor is horizontal?

Go to step 2.

Go to step 5.

2

CHECK POOR CONTACT IN CONNECTOR.

Is there poor contact in connec-
tors between ABSCM&H/U and
G sensor?

Repair the connec-
tor.

Go to step 3.

3

CHECK ABSCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to ABS(diag)-20,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
ABS(diag)-19, Inspection Mode.>
4) Read the DTC.

Is the same DTC displayed?

Replace the
ABSCM only. <Ref.
to ABS-8,
REPLACEMENT,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>

Go to step 4.

4

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
ABS(diag)-29, List
of Diagnostic Trou-
ble Code (DTC).>

Temporary poor
contact occurs.

5

CHECK INPUT VOLTAGE OF G SENSOR.
1) Turn the ignition switch to OFF.
2) Remove the console box.
3) Remove the G sensor from vehicle. (Do not
disconnect the connector.)
4) Turn the ignition switch to ON.
5) Measure the voltage between G sensor
connector terminals.

Connector & terminal

(B292) No. 1 (+) — No. 3 (–):

Is the voltage 4.75 — 5.25 V?

Go to step 6.

Repair the harness
connector between
the G sensor and
ABSCM&H/U.

6

CHECK OPEN CIRCUIT IN G SENSOR OUT-
PUT HARNESS AND GROUND HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect the ABSCM&H/U connectors.
3) Measure the resistance between
ABSCM&H/U connector terminals.

Connector & terminal

(B301) No. 21 — No. 10:

Is the resistance 3.6 — 3.8 k

:? Go to step 7.

Repair the harness
connector between
the G sensor and
ABSCM&H/U.

7

CHECK GROUND SHORT IN G SENSOR
OUTPUT HARNESS.
1) Disconnect the connector from the G sen-
sor.
2) Measure the resistance between the
ABSCM&H/U connector and chassis ground.

Connector & terminal

(B301) No. 21 — Chassis ground:

Is the resistance 1 M

: or

more?

Go to step 8.

Repair the harness
between the G
sensor and
ABSCM&H/U.

8

CHECK G SENSOR.
1) Connect the connector to G sensor.
2) Connect the connector to ABSCM&H/U.
3) Turn the ignition switch to ON.
4) Measure the voltage between G sensor
connector terminals.

Connector & terminal

(B292) No. 2 (+) — No. 3 (–):

Is the voltage 2.1 — 2.5 V when
G sensor is in horizontal posi-
tion?

Go to step 9.

Replace the G sen-
sor. <Ref. to ABS-
18, G Sensor.>

ABS(diag)-58

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ABS (DIAGNOSTICS)

9

CHECK G SENSOR.
Measure the voltage between G sensor con-
nector terminals.

Connector & terminal

(B292) No. 2 (+) — No. 3 (–):

Is the voltage 3.6 — 4.1 V when
the G sensor is inclined forward
to 90°?

Go to step 10.

Replace the G sen-
sor. <Ref. to ABS-
18, G Sensor.>

10

CHECK G SENSOR.
Measure the voltage between G sensor con-
nector terminals.

Connector & terminal

(B292) No. 2 (+) — No. 3 (–):

Is the voltage 0.5 — 1.0 V when
G sensor is inclined back 90°?

Go to step 11.

Replace the G sen-
sor. <Ref. to ABS-
18, G Sensor.>

11

CHECK POOR CONTACT IN CONNECTOR.
Turn the ignition switch to OFF.

Is there poor contact in connec-
tors between ABSCM&H/U and
G sensor?

Repair the connec-
tor.

Go to step 12.

12

CHECK ABSCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to ABS(diag)-20,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
ABS(diag)-19, Inspection Mode.>
4) Read the DTC.

Is the same DTC displayed?

Replace the
ABSCM only. <Ref.
to ABS-8,
REPLACEMENT,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>

Go to step 13.

13

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
ABS(diag)-29, List
of Diagnostic Trou-
ble Code (DTC).>

Temporary poor
contact occurs.

Step

Check

Yes

No