Subaru Legacy III (2000-2003 year). Manual - part 767

VDC-104

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

18

CHECK GROUND SHORT IN CONTACT 
POINT CIRCUIT OF RELAY BOX.
Measure resistance between VDCH/U connec-
tor and chassis ground.

Connector & terminal

(VDC1) No. 2 — Chassis ground:

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 19.

Replace relay box 
and check fuse 
No. 8.

19

CHECK BATTERY SHORT IN CONTACT 
POINT CIRCUIT OF RELAY BOX.
Measure voltage between VDCH/U connector 
and chassis ground.

Connector & terminal

(VDC1) No. 2 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified 
value?

1 V

Go to step 20.

Replace relay box. 
Check fuse No. 8.

20

CHECK BATTERY SHORT IN CONTACT 
POINT CIRCUIT OF RELAY BOX.
1) Turn ignition switch to ON.
2) Measure voltage between VDCH/U con-

nector and chassis ground.

Connector & terminal

(VDC1) No. 2 (+) — Chassis ground (

−−−−

):

Is the measured value less than the speci-
fied value?

1 V

Go to step 21.

Replace relay box. 
Check fuse No. 8.

21

CHECK RESISTANCE OF INLET AND CUT 
SOLENOID VALVES.
1) Disconnect connector from VDCH/U.
2) Measure resistance between VDCH/U con-

nector terminals.

Connector & terminal

(VDC5) No. 8 — (VDC2) No. 2:
(VDC5) No. 5 — (VDC2) No. 2:
(VDC5) No. 6 — (VDC2) No. 2:
(VDC5) No. 7 — (VDC2) No. 2:
(VDC5) No. 9 — (VDC2) No. 2:
(VDC5) No. 12 — (VDC2) No. 2:

Is the measured value within the specified 
range?

8.04 — 9.04 

Ω

Go to step 22.

Replace VDCH/U.  
<Ref. to VDC-8, 
VDC Control Mod-
ule (VDCCM).>

22

CHECK RESISTANCE OF OUTLET SOLE-
NOID VALVE.
Measure resistance between VDCH/U connec-
tor terminals.

Connector & terminal

(VDC5) No. 4 — (VDC2) No. 2:
(VDC5) No. 1 — (VDC2) No. 2:
(VDC5) No. 2 — (VDC2) No. 2:
(VDC5) No. 3 — (VDC2) No. 2:
(VDC5) No. 10 — (VDC2) No. 2:
(VDC5) No. 11 — (VDC2) No. 2:

Is the measured value within the specified 
range?

4.04 — 4.54 

Ω

Go to step 23.

Replace VDCH/U.  
<Ref. to VDC-8, 
VDC Control Mod-
ule (VDCCM).>

Step

Value

Yes

No

VDC-105

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

23

CHECK GROUND SHORT OF SOLENOID 
VALVE.
Measure resistance between VDCH/U connec-
tor and chassis ground.

Connector & terminal

(VDC2) No. 2 — Chassis ground:

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 24.

Replace VDCH/U 
and check all 
fuses.  <Ref. to 
VDC-8, VDC Con-
trol Module 
(VDCCM).>

24

CHECK BATTERY SHORT OF SOLENOID 
VALVE.
Measure voltage between VDCH/U connector 
and chassis ground.

Connector & terminal

(VDC2) No. 2 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified 
value?

1 V

Go to step 25.

Replace VDCH/U 
and check all 
fuses.  <Ref. to 
VDC-8, VDC Con-
trol Module 
(VDCCM).>

25

CHECK BATTERY SHORT OF SOLENOID 
VALVE.
1) Turn ignition switch to ON.
2) Measure voltage between VDCH/U con-

nector and chassis ground.

Connector & terminal

(VDC2) No. 2 (+) — Chassis ground (

−−−−

):

Is the measured value less than the speci-
fied value?

1 V

Go to step 26.

Replace VDCH/U 
and check all 
fuses.  <Ref. to 
VDC-8, VDC Con-
trol Module 
(VDCCM).>

26

CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM.
3) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

(F87) No. 30 (+) — Chassis ground (

−−−−

):

(F87) No. 24 (+) — Chassis ground (

−−−−

):

(F87) No. 23 (+) — Chassis ground (

−−−−

):

(F87) No. 31 (+) — Chassis ground (

−−−−

):

(F87) No. 26 (+) — Chassis ground (

−−−−

):

(F87) No. 25 (+) — Chassis ground (

−−−−

):

(F87) No. 3 (+) — Chassis ground (

−−−−

):

(F87) No. 51 (+) — Chassis ground (

−−−−

):

(F87) No. 50 (+) — Chassis ground (

−−−−

):

(F87) No. 4 (+) — Chassis ground (

−−−−

):

(F87) No. 2 (+) — Chassis ground (

−−−−

):

(F87) No. 29 (+) — Chassis ground (

−−−−

):

Is the measured value less than the speci-
fied value?

1 V

Go to step 27.

Repair harness 
between VDCH/U 
and VDCCM and 
check all fuses.

Step

Value

Yes

No

VDC-106

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

27

CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

(F87) No. 30 (+) — Chassis ground (

−−−−

):

(F87) No. 24 (+) — Chassis ground (

−−−−

):

(F87) No. 23 (+) — Chassis ground (

−−−−

):

(F87) No. 31 (+) — Chassis ground (

−−−−

):

(F87) No. 26 (+) — Chassis ground (

−−−−

):

(F87) No. 25 (+) — Chassis ground (

−−−−

):

(F87) No. 3 (+) — Chassis ground (

−−−−

):

(F87) No. 51 (+) — Chassis ground (

−−−−

):

(F87) No. 50 (+) — Chassis ground (

−−−−

):

(F87) No. 4 (+) — Chassis ground (

−−−−

):

(F87) No. 2 (+) — Chassis ground (

−−−−

):

(F87) No. 29 (+) — Chassis ground (

−−−−

):

Is the measured value less than the speci-
fied value?

1 V

Go to step 28.

Repair harness 
between VDCH/U 
and VDCCM and 
check all fuses.

28

CHECK GROUND SHORT OF HARNESS.
1) Turn ignition switch to OFF.
2) Measure resistance between VDCCM con-

nector and chassis ground.

Connector & terminal

(F87) No. 30 — Chassis ground:
(F87) No. 24 — Chassis ground:
(F87) No. 23 — Chassis ground:
(F87) No. 31 — Chassis ground:
(F87) No. 26 — Chassis ground:
(F87) No. 25 — Chassis ground:
(F87) No. 3 — Chassis ground:
(F87) No. 51 — Chassis ground:
(F87) No. 50 — Chassis ground:
(F87) No. 4 — Chassis ground:
(F87) No. 2 — Chassis ground:
(F87) No. 29 — Chassis ground:

Does the measured value exceed the spec-
ified value?

1 M

Ω

Go to step 29.

Repair harness 
between VDCH/U 
and VDCCM.

29

CHECK HARNESS/CONNECTOR BETWEEN 
VDCCM AND VDCH/U.
1) Connect connector (F91) to VDCH/U.
2) Measure resistance between VDCCM con-

nector and VDCH/U connector.

Connector & terminal

(F87) No. 30 — (VDC2) No. 2:
(F87) No. 24 — (VDC2) No. 2:
(F87) No. 23 — (VDC2) No. 2:
(F87) No. 31 — (VDC2) No. 2:
(F87) No. 26 — (VDC2) No. 2:
(F87) No. 25 — (VDC2) No. 2:

Is the measured value within the specified 
range?

8.0 — 10.0 

Ω

Go to step 30.

Repair harness/
connector 
between VDCH/U 
and VDCCM.

Step

Value

Yes

No

VDC-107

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR

30

CHECK HARNESS/CONNECTOR BETWEEN 
VDCCM AND VDCH/U.
Measure resistance between VDCCM connec-
tor and VDCH/U connector.

Connector & terminal

(F87) No. 3 — (VDC2) No. 2:
(F87) No. 51 — (VDC2) No. 2:
(F87) No. 50 — (VDC2) No. 2:
(F87) No. 4 — (VDC2) No. 2:
(F87) No. 2 — (VDC2) No. 2:
(F87) No. 29 — (VDC2) No. 2:

Is the measured value within the specified 
range?

4.0 — 6.0 

Ω

Go to step 31.

Repair harness/
connector 
between VDCH/U 
and VDCCM.

31

CHECK POOR CONTACT IN CONNECTORS.
Is there poor contact in connector between 
VDCCM and VDCH/U?

There is poor contact.

Repair connector.

Go to step 32.

32

CHECK VDCCM.
1) Connect all connectors.
2) Erase the memory.
3) Perform inspection mode.
4) Read out the diagnostic trouble code.

Is the same diagnostic trouble code as in 
the current diagnosis still being output?

Same DTC indicated.

Replace VDCCM.  
<Ref. to VDC-8, 
VDC Control Mod-
ule (VDCCM).>

Go to step 33.

33

CHECK ANY OTHER DIAGNOSTIC TROU-
BLE CODES APPEARANCE.
Are other diagnostic trouble codes being out-
put?

Other DTC indicated.

Proceed with the 
diagnosis corre-
sponding to the 
diagnostic trouble 
code.

A temporary poor 
contact.

Step

Value

Yes

No