Subaru Legacy (2005 year). Service manual — part 802

VDC(diag)-73

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AG:DTC C0051 VALVE RELAY OFF MALFUNCTION

DTC DETECTING CONDITION:
Defective valve relay
TROUBLE SYMPTOM:
• ABS does not operate.
• EBD does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00320

B310

B310

E

5

6

VDCCM & H/U

14

M

MAIN SBF

SBF-6

No.1

No.33

E

22 23 24 25 26

21

20

19

16

15

14

13

12

11

4

5

6

7

8

9

10

3

2

1

17 18

38 39 40 41 42

37

36

35

32

31

30

29

28

27

33 34

BATTERY

IGNITION
SWITCH

VALVE RELAY

SOLENOID

VALVE

PUMP MOTOR

FL INLET

RL INLET

FR INLET

RR INLET

FL OUTLET

RL OUTLET

FR OUTLET

RR OUTLET

MOTOR RELAY

PRIMARY SUCTION

PRIMARY CUT

SECONDARY CUT

SECONDARY SUCTION

VDC(diag)-74

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK INPUT VOLTAGE FOR VDCCM&H/
U.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from VDCCM&H/
U.
3) Run the engine at idle.
4) Measure the voltage between VDCCM&H/
U connector and chassis ground.

Connector & terminal

(B310) No. 5 (+) — Chassis ground (

−

):

Is the voltage 10 — 15 V?

Go to step 2.

Repair the har-
ness connector
between battery
and VDCCM&H/U.

2

CHECK GROUND CIRCUIT OF VDCCM&H/U.
1) Turn the ignition switch to OFF.
2) Measure the resistance between
VDCCM&H/U connector and chassis ground.

Connector & terminal

(B310) No. 6 — Chassis ground:

Is the resistance less than 0.5
Ω?

Go to step 3.

Repair the
VDCCM&H/U
ground harness.

3

CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-

nector between generator, bat-
tery and VDCCM&H/U?

Repair the con-
nector.

Go to step 4.

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.

Temporary poor
contact occurs.

VDC(diag)-75

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

AH:DTC C0051 VALVE RELAY MALFUNCTION

DTC DETECTING CONDITION:
Defective valve relay
TROUBLE SYMPTOM:
• ABS does not operate.
• EBD does not operate.
• VDC does not operate.
WIRING DIAGRAM:

VDC00320

B310

B310

E

5

6

VDCCM & H/U

14

M

MAIN SBF

SBF-6

No.1

No.33

E

22 23 24 25 26

21

20

19

16

15

14

13

12

11

4

5

6

7

8

9

10

3

2

1

17 18

38 39 40 41 42

37

36

35

32

31

30

29

28

27

33 34

BATTERY

IGNITION
SWITCH

VALVE RELAY

SOLENOID

VALVE

PUMP MOTOR

FL INLET

RL INLET

FR INLET

RR INLET

FL OUTLET

RL OUTLET

FR OUTLET

RR OUTLET

MOTOR RELAY

PRIMARY SUCTION

PRIMARY CUT

SECONDARY CUT

SECONDARY SUCTION

VDC(diag)-76

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

Step

Check

Yes

No

1

CHECK INPUT VOLTAGE FOR VDCCM&H/
U.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from VDCCM&H/
U.
3) Run the engine at idle.
4) Measure the voltage between VDCCM&H/
U connector and chassis ground.

Connector & terminal

(B310) No. 14 (+) — Chassis ground (

−

):

(B310) No. 5 (+) — Chassis ground (

−

):

Is the voltage 10 — 15 V?

Go to step 2.

Repair the power
supply circuit.

2

CHECK INPUT VOLTAGE FOR VDCCM&H/
U.
Calculate the voltage difference measured in
step 1.
A:(B310) No. 14 (+) — Chassis ground (

−):

B:(B310) No. 5 (+) — Chassis ground (

−):

Is the voltage difference
between A and B more than 2
V?

Repair the power
supply circuit.

Go to step 3.

3

CHECK GROUND CIRCUIT OF VDCCM&H/U.
1) Turn the ignition switch to OFF.
2) Measure the resistance between
VDCCM&H/U connector and chassis ground.

Connector & terminal

(B310) No. 6 — Chassis ground:

Is the resistance less than 0.5
Ω?

Go to step 4.

Repair the
VDCCM&H/U
ground harness.

4

CHECK VALVE RELAY FOR VDCCM&H/U.
Measure the resistance between VDCCM&H/U
connector terminals.

Connector & terminal

(B310) No. 5 — (B310) No. 6:

Is the resistance more than 1
M

Ω?

Go to step 5.

Replace the
VDCCM&H/U.

5

CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-

nector between generator, bat-
tery and VDCCM&H/U?

Repair the con-
nector.

Go to step 6.

6

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 7.

7

CHECK OTHER DTC DETECTION.

Is any other DTC displayed?

Perform the diag-
nosis according to
DTC.

Temporary poor
contact occurs.