Subaru Legacy IV (2008 year). Manual — part 944

VDC(diag)-91

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AT:DTC C0072 CHANGE RANGE OF YAW RATE SENSOR SIGNAL IS TOO BIG

DTC DETECTING CONDITION:
Defective yaw rate sensor
TROUBLE SYMPTOM:
VDC does not operate.
WIRING DIAGRAM:

Step

Check

Yes

No

1

CHECK DRIVING PLACE.
Check if the vehicle ran the road with banks or
sandy surface (which does not mean a dirt
road).

Did the vehicle run the road
with banks or sandy surface
(which does not mean a dirt
road)?

VDCCM&H/U may
record DTC when
the vehicle ran the
road with banks or
sandy surface
(which does not
mean a dirt road).

Go to step 2.

2

CHECK YAW RATE & LATERAL G SENSOR
INSTALLATION.

Is the yaw rate & lateral G sen-
sor installation bolt tightened to
7.5 N·m (0.76 kgf-m, 5.5 ft-lb)?

Go to step 3.

Tighten the yaw
rate & lateral G
sensor installation
bolt.

VDC00473

1 2 3 4

B310

VDCCM & H/U

25

10

35

B231

B230

2

4

1

1

4

2

3

3

STEERING
ANGLE
SENSOR

YAW RATE &
LATERAL G
SENSOR

E

E

B231

SBF-6

MAIN SBF

No.33

E

IGNITION
SWITCH

BATTERY

B310

4 5 6 7 8 9

26 27 28 29 30

2 3

1

31 32 33 34 35 36

10 11

14 15 16 17 18 19

37 38 39 40

12 13

41 42 43 44 45 46

20 21

23

24

22

25

B230

1

2

3

4

TWISTED PAIR LINE

TWISTED PAIR LINE

B365

B170

CAN
JOINT
CONNECTOR

4

*

3

*

4

3

*

*

2

1 :

:

*

*

CAN
JOINT
CONNECTOR

TERMINAL No. OPTIONAL
ARRANGEMENT AMONG
1, 2, 3,11,12 AND 13

TERMINAL No. OPTIONAL
ARRANGEMENT AMONG
8, 9, 10, 18, 19 AND 20

4

3 :

:

*

*

TERMINAL No. OPTIONAL
ARRANGEMENT AMONG
1, 2, 5 AND 6

TERMINAL No. OPTIONAL
ARRANGEMENT AMONG
3, 4, 7 AND 8

2

1

* *

2

1

* *

2

1

*

*

TWISTED
PAIR LINE

B170

3 4

5 6

1 2

7 8

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

B365

VDC(diag)-92

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

3

CHECK YAW RATE & LATERAL G SENSOR
POWER SUPPLY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from yaw rate &
lateral G sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between yaw rate &
lateral G sensor and chassis ground.

Connector & terminal

(B230) No. 1 (+) — Chassis ground (–):

Is the voltage 10 — 15 V?

Go to step 4.

Repair the power
supply circuit of the
yaw rate & lateral
G sensor.

4

CHECK YAW RATE & LATERAL G SENSOR
GROUND CIRCUIT.
Measure the resistance between the yaw rate &
lateral G sensor and chassis ground.

Connector & terminal

(B230) No. 4 — Chassis ground:

Is the resistance less than 0.5

:? Go to step 5.

Repair the ground
circuit of the yaw
rate & lateral G
sensor.

5

CHECK OUTPUT OF YAW RATE & LATERAL
G SENSOR WITH SUBARU SELECT MONI-
TOR.
1) Drive the vehicle on a flat road.
2) Park the vehicle straight.
3) Select {Current Data Display & Save} in the
Subaru Select Monitor.
4) Read the yaw rate output displayed on dis-
play.

Is the reading indicated on
monitor display –4 — 4 deg/s?

Go to step 6.

Replace the yaw
rate & lateral G
sensor.

6

CHECK YAW RATE & LATERAL G SENSOR.
1) Turn the ignition switch to OFF.
2) Connect all connectors.
3) Clear the memory. <Ref. to VDC(diag)-23,
Clear Memory Mode.>
4) Perform the Inspection Mode. <Ref. to
VDC(diag)-22, Inspection Mode.>
5) Read the DTC.

Is the same DTC displayed?

Go to step 7.

Go to step 8.

7

CHECK VDCCM&H/U.
1) Turn the ignition switch to OFF.
2) Replace the yaw rate & lateral G sensor.
3) Clear the memory. <Ref. to VDC(diag)-23,
Clear Memory Mode.>
4) Perform the Inspection Mode. <Ref. to
VDC(diag)-22, Inspection Mode.>
5) Read the DTC.

Is the same DTC displayed?

Replace the
VDCCM only.
<Ref. to VDC-10,
REPLACEMENT,
VDC Control Mod-
ule and Hydraulic
Control Unit
(VDCCM&H/U).>

Go to step 9.

8

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC. <Ref. to
VDC(diag)-34, List
of Diagnostic Trou-
ble Code (DTC).>

Temporary poor
contact occurs.

9

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC. <Ref. to
VDC(diag)-34, List
of Diagnostic Trou-
ble Code (DTC).>

Malfunction is
found in original
yaw rate & lateral
G sensor.

Step

Check

Yes

No

VDC(diag)-93

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AU:DTC C0073 LATERAL G SENSOR COMMUNICATION

DTC DETECTING CONDITION:
Communication failure between lateral G sensor and VDCCM
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.

NOTE:
For the diagnostic procedure, refer to DTC C0072 “YAW RATE SENSOR COMMUNICATION”. <Ref. to
VDC(diag)-94, DTC C0072 YAW RATE SENSOR COMMUNICATION, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>

VDC(diag)-94

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AV:DTC C0072 YAW RATE SENSOR COMMUNICATION

DTC DETECTING CONDITION:
Communication failure between yaw rate sensor and VDCCM
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

Step

Check

Yes

No

1

CHECK POWER SUPPLY FOR YAW RATE &
LATERAL G SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from yaw rate &
lateral G sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between yaw rate &
lateral G sensor and chassis ground.

Connector & terminal

(B230) No. 1 (+) — Chassis ground (–):

Is the voltage 10 — 15 V?

Go to step 2.

Repair the power
supply circuit of the
yaw rate & lateral
G sensor.

VDC00473

1 2 3 4

B310

VDCCM & H/U

25

10

35

B231

B230

2

4

1

1

4

2

3

3

STEERING
ANGLE
SENSOR

YAW RATE &
LATERAL G
SENSOR

E

E

B231

SBF-6

MAIN SBF

No.33

E

IGNITION
SWITCH

BATTERY

B310

4 5 6 7 8 9

26 27 28 29 30

2 3

1

31 32 33 34 35 36

10 11

14 15 16 17 18 19

37 38 39 40

12 13

41 42 43 44 45 46

20 21

23

24

22

25

B230

1

2

3

4

TWISTED PAIR LINE

TWISTED PAIR LINE

B365

B170

CAN
JOINT
CONNECTOR

4

*

3

*

4

3

*

*

2

1 :

:

*

*

CAN
JOINT
CONNECTOR

TERMINAL No. OPTIONAL
ARRANGEMENT AMONG
1, 2, 3,11,12 AND 13

TERMINAL No. OPTIONAL
ARRANGEMENT AMONG
8, 9, 10, 18, 19 AND 20

4

3 :

:

*

*

TERMINAL No. OPTIONAL
ARRANGEMENT AMONG
1, 2, 5 AND 6

TERMINAL No. OPTIONAL
ARRANGEMENT AMONG
3, 4, 7 AND 8

2

1

* *

2

1

* *

2

1

*

*

TWISTED
PAIR LINE

B170

3 4

5 6

1 2

7 8

1 2 3 4 5 6 7 8 9 10

11 12 13 14 15 16 17 18 19 20

B365