Subaru Legacy IV (2008 year). Manual — part 938

VDC(diag)-67

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AF:DTC C0052 MOTOR AND MOTOR RELAY ON FAILURE

DTC DETECTING CONDITION:
• Defective motor relay
• Defective harness connector
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
• EBD may not operate.
WIRING DIAGRAM:

B310

E

23

25

VDCCM & H/U

28

PUMP MOTOR

M

FL INLET

MAIN SBF

SBF-6

No.33

E

BATTERY

IGNITION
SWITCH

SOLENOID VALVE

MOTOR RELAY

VALVE RELAY

FR INLET

RL INLET

RR INLET

FL OUTLET

FR OUTLET

RL OUTLET

RR OUTLET

PRIMARY CUT

SECONDARY CUT

PRIMARY SUCTION

SBF-1

E

22

SECONDARY SUCTION

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

VDC00467

VDC(diag)-68

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AG:DTC C0052 MOTOR MALFUNCTION

DTC DETECTING CONDITION:
• Defective motor
• Defective motor relay
• Defective harness connector
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
• EBD may not operate.

NOTE:
For the diagnostic procedure, refer to DTC C0052 “MOTOR/MOTOR RELAY OFF FAILURE”. <Ref. to
VDC(diag)-65, DTC C0052 MOTOR AND MOTOR RELAY OFF FAILURE, Diagnostic Procedure with Diag-
nostic Trouble Code (DTC).>

Step

Check

Yes

No

1

CHECK VDCCM&H/U MOTOR RELAY.
1) Disconnect the connector from the
VDCCM&H/U.
2) Measure the resistance between
VDCCM&H/U connector terminals.

Terminals

No. 23 — No. 22:

Is the resistance 1 M

: or

more?

Go to step 2.

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

2

CHECK VDCCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to VDC(diag)-23,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
VDC(diag)-22, Inspection Mode.>
4) 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 3.

3

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.

NOTE:
Though the ABS
warning light re-
mains on at this
time, this is normal.
Drive the vehicle at
12 km/h (7 MPH)
or more in order to
turn ABS warning
light off. Be sure to
drive the vehicle
and check that the
warning light goes
off.

VDC(diag)-69

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

AH:DTC C0054 BLS CIRCUIT OPEN

DTC DETECTING CONDITION:
Defective stop light switch
TROUBLE SYMPTOM:
• ABS does not operate.
• VDC does not operate.
WIRING DIAGRAM:

1 2
3 4

9

4

7

6

2

1
5

3
8

B65

B159

B310

30

VDCCM & H/U

59

B159

B225

B65

3

2

E

MAIN SBF

SBF-2

No.8

7.5A

3

4

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

VDC00502

B225

13
14

15 16

17

27

24

25
26

20

21
22

23

29
30

31

28

32

35

33
34

37
38

39

36

40

8

9

10

11 12

1

2

5

3

4

7

6

19

18

BATTERY

STOP LIGHT
SWITCH

FUSE
(RELAY BLOCK)

VDC(diag)-70

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

VEHICLE DYNAMICS CONTROL (VDC) (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK OUTPUT OF STOP LIGHT SWITCH
WITH 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 output in Subaru
Select Monitor.

Is OFF displayed on the display
screen?

Go to step 2.

Go to step 3.

2

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

Is ON displayed on the display
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 fuse (B225) in the relay block.

Is the fuse OK?

Go to step 5.

Replace the fuse.

5

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

Connector & terminal

(B310) No. 30 (+) — Chassis ground (–):

Is the voltage 10 — 15 V?

Go to step 6.

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

6

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

tor between stop light switch
and VDCCM&H/U?

Repair the connec-
tor.

Go to step 7.

7

CHECK VDCCM&H/U.
1) Connect all connectors.
2) Clear the memory. <Ref. to VDC(diag)-23,
Clear Memory Mode.>
3) Perform the Inspection Mode. <Ref. to
VDC(diag)-22, Inspection Mode.>
4) 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 8.

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.