Subaru Legacy (2005 year). Manual - part 806

VDC(diag)-89

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK STOP LIGHT SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the stop light switch connector.
3) Measure the resistance of stop light switch 
terminals.

Is the resistance more than 1 
M

Ω when switch is OFF (when 

pedal is not depressed)?

Go to step 2.

Replace the stop 
light switch.

2

INTERVIEWING CUSTOMERS.
Make sure that the operation was performed in 
which accelerator pedal and brake pedal were 
depressed simultaneously (with depressing 
brake pedal with left foot).

Were the acceleration pedal 
and brake pedal depressed 
simultaneously during driving?

System is in good 
order. (DTC may 
be recorded while 
brake is applied 
during driving.)

Go to step 3.

3

CHECK VDCCM&H/U.
1) Connect all the connectors.
2) Perform the clear memory mode.
3) Perform the inspection mode.
4) Read the DTC.

Is the same DTC displayed?

Replace the 
VDCCM&H/U. 
<Ref. to VDC-7, 
VDC Control Mod-
ule and Hydraulic 
Control Unit 
(VDCCM&H/U).>

Go to step 4.

4

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to 
DTC. <Ref. to 
VDC(diag)-38, List 
of Diagnostic Trou-
ble Code (DTC).>

Temporary poor 
contact occurs.

VDC(diag)-90

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AQ:DTC C0057 ECM COMMUNICATION

DTC DETECTING CONDITION:
No CAN signal from ECM.
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.

AR:DTC C0057 ECM CONTROL

DTC DETECTING CONDITION:
Cooperation control prohibition of ECM
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.

NOTE:
Warning light goes off if the cooperation control of ECM returns.

Step

Check

Yes

No

1

CHECK LAN SYSTEM.
Perform the diagnosis for LAN system. <Ref. to 
LAN(diag)-24, OPERATION, Read Diagnostic 
Trouble Code (DTC).>

Is there any fault in LAN sys-
tem?

Perform the diag-
nosis according to 
DTC for LAN sys-
tem.

Go to step 2.

2

CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in ECM 

connector?

Repair the con-
nector.

Go to step 3.

3

CHECK ECM.

Is ECM normal?

Go to step 4.

Replace the ECM.

4

CHECK VDCCM&H/U.
1) Connect all the connectors.
2) Perform the clear memory mode.
3) Perform the inspection mode.
4) Read the DTC.

Is the same DTC displayed?

Replace the 
VDCCM&H/U. 
<Ref. to VDC-7, 
VDC Control Mod-
ule and Hydraulic 
Control Unit 
(VDCCM&H/U).>

Go to step 5.

5

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to 
DTC.

It results from a 
temporary noise 
interference.

Step

Check

Yes

No

1

CHECK WARNING LIGHT.
Drive the vehicle at speed of 10 km/h or more 
for one minute or more, check the VDC warn-
ing light illuminates.

Does the VDC warning light 
illuminate?

Go to step 2.

VDC is normal. 
Perform the clear 
memory mode.

NOTE:
DTC may be re-
corded when
cranking during
driving.

2

CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in ECM 

connector?

Repair the con-
nector.

Go to step 3.

3

CHECK ECM.

Is ECM normal?

Go to step 4.

Replace the ECM.

4

CHECK VDCCM&H/U.
1) Connect all the connectors.
2) Perform the clear memory mode.
3) Perform the inspection mode.
4) Read the DTC.

Is the same DTC displayed?

Replace the 
VDCCM&H/U. 
<Ref. to VDC-7, 
VDC Control Mod-
ule and Hydraulic 
Control Unit 
(VDCCM&H/U).>

Go to step 5.

5

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to 
DTC.

It results from a 
temporary noise 
interference.

VDC(diag)-91

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AS:DTC C0071 EXCESSIVE STEERING ANGLE SENSOR OUTPUT OFFSET

DTC DETECTING CONDITION:
Defective steering angle sensor
TROUBLE SYMPTOM:
VDC does not operate.
WIRING DIAGRAM:
• LHD model

VDC00327

30

29

13

B231

B234

E

2

4

1

3

3

1

4

2

B310

B310

VDCCM & H/U

1 2 3 4

11 12 13 14
27 28 29 30

15 16 17 18
31 32 33 34

19 20 21 22
35 36 37 38

23 24 25 26
39 40 41 42

5

6

7

8

9

10

1 2 3 4

B231

TWISTED WIRE

STEERING
ANGLE SENSOR

B234

3 4

5 6

1 2

7 8

B352

3

1

4

2

B352

VDC(diag)-92

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

• RHD model

VDC00247

30

29

13

B231

E

2

4

1

3

B310

B310

VDCCM & H/U

1 2 3 4

11 12 13 14
27 28 29 30

15 16 17 18
31 32 33 34

19 20 21 22
35 36 37 38

23 24 25 26
39 40 41 42

5

6

7

8

9

10

1 2 3 4

B231

TWISTED WIRE

STEERING
ANGLE SENSOR