Subaru Legacy III (2000-2003 year). Manual — part 792

VDC-204

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

7

CHECK POWER SUPPLY FOR VALVE RE-
LAY.
1) Disconnect connector (F89) from relay box.
2) Turn ignition switch to ON.
3) Measure voltage between relay box con-

nector and chassis ground.

Connector & terminal

(F89) No. 1 (+) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

10 — 15 V

Go to step 8.

Repair harness
between battery
and relay box con-
nector. Check fuse
No. 8.

8

CHECK OPEN CIRCUIT AND GROUND
SHORT IN POWER SUPPLY CIRCUIT OF
RELAY BOX.
1) Disconnect connector (VDC1) from VDCH/

U.

2) Connect connector (F89) to relay box.
3) Turn ignition switch to ON.
4) Measure voltage of relay box.

Connector & terminal

(VDC6) No. 87 (

++++

) — Chassis ground (

−−−−

):

Is the measured value within the specified
range?

10 — 15 V

Go to step 9.

Replace relay box
and check fuse
No. 8.

9

CHECK OPEN CIRCUIT IN CONTROL CIR-
CUIT OF RELAY BOX.
1) Turn ignition switch to OFF.
2) Disconnect connector (F90) from relay box.
3) Measure resistance between relay box con-

nector and valve relay installing point.

Connector & terminal

(VDC4) No. 5 — (VDC6) No. 85:
(VDC4) No. 1 — (VDC6) No. 86:

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

0.5

Ω

Go to step 10.

Replace relay box.

10

CHECK GROUND SHORT IN CONTACT
POINT CIRCUIT OF RELAY BOX.
Measure resistance between relay box con-
nector and chassis ground.

Connector & terminal

(VDC4) No. 5 — Chassis ground:
(VDC4) No. 1 — Chassis ground:

Does the measured value exceed the specified
value?

1 M

Ω

Go to step 11.

Replace relay box
and check fuse
SBF6.

11

CHECK OPEN CIRCUIT IN CONTROL SYS-
TEM HARNESS OF VALVE RELAY.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM.
3) Measure resistance between VDCCM con-

nector and relay box connector.

Connector & terminal

(F87) No. 47 — (F90) No. 5:
(F87) No. 27 — (F90) No. 1:

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

0.5

Ω

Go to step 12.

Repair harness
between VDCCM
and relay box.

Step

Value

Yes

No

VDC-205

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

12

CHECK GROUND SHORT IN CONTROL
SYSTEM HARNESS OF VALVE RELAY.
Measure resistance between VDCCM connec-
tor and chassis ground.

Connector & terminal

(F87) No. 47 — Chassis ground:
(F87) No. 27 — Chassis ground:

Does the measured value exceed the specified
value?

1 M

Ω

Go to step 13.

Repair harness
between VDCCM
and relay box.

13

CHECK OPEN CIRCUIT IN CONTACT POINT
CIRCUIT OF RELAY BOX.
Measure resistance between VDCH/U connec-
tor and valve relay installing point.

Connector & terminal

(VDC1) No. 2 — (VDC6) No. 30:

Is the measured value less than the specified
value?

0.5

Ω

Go to step 14.

Replace relay box.

14

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 15.

Replace relay box
and check fuse
No. 8.

15

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 16.

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

16

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 17.

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

Step

Value

Yes

No

VDC-206

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

17

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 18.

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

18

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 19.

Repair harness
between VDCH/U
and VDCCM.

19

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 & 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 20.

Repair harness/
connector
between VDCH/U
and VDCCM.

20

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

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 21.

Repair harness/
connector
between VDCH/U
and VDCCM.

21

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 22.

Step

Value

Yes

No

VDC-207

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

22

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 23.

23

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