Subaru Legacy III (2000-2003 year). Manual - part 796

VDC-220

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

6

CHECK OPEN CIRCUIT IN CONTACT POINT 
CIRCUIT OF RELAY BOX.
1) Turn ignition switch to OFF.
2) Disconnect connectors (VDC2, F90) from 

relay box.

3) Measure resistance between relay box con-

nector unit and motor relay installing por-
tion.

Connector & terminal

(VDC1) No. 1 — (VDC7) No. 30:

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

0.5 

Ω

Go to step 7.

Replace relay box.

7

CHECK OPEN CIRCUIT IN MONITOR SYS-
TEM CIRCUIT OF RELAY BOX.
Measure resistance between relay box con-
nector and motor relay installing point.

Connector & terminal

(VDC4) No. 6 — (VDC7) No. 30:

Is the measured value less than the specified 
value?

0.5 

Ω

Go to step 8.

Replace relay box.

8

CHECK OPEN CIRCUIT IN CONTROL CIR-
CUIT OF RELAY BOX.
Measure resistance between motor relay 
installing point and relay box connector.

Connector & terminal

(VDC4) No. 4 — (VDC7) No. 86:

Is the measured value less than the specified 
value?

0.5 

Ω

Go to step 9.

Replace relay box.

9

CHECK OPEN CIRCUIT IN CONTROL CIR-
CUIT OF RELAY BOX.
1) Remove valve relay from relay box.
2) Measure resistance between motor relay 

installing point and valve relay installing 
point.

Connector & terminal

(VDC7) No. 85 — (VDC6) No. 30:

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 CIRCUIT OF 
RELAY BOX.
Measure resistance between relay box con-
nector and chassis ground.

Connector & terminal

(VDC4) No. 4 — Chassis ground:
(VDC4) No. 6 — Chassis ground:

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 11.

Replace relay box.

11

CHECK BATTERY SHORT IN CIRCUIT OF 
RELAY BOX.
Measure voltage between relay box connector 
and chassis ground.

Connector & terminal

(VDC4) No. 6 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified 
value?

1 V

Go to step 12.

Replace relay box.

Step

Value

Yes

No

VDC-221

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

12

CHECK BATTERY SHORT IN CIRCUIT OF 
RELAY BOX.
1) Turn ignition switch to ON.
2) Measure voltage between relay box con-

nector and chassis ground.

Connector & terminal

(VDC4) No. 6 (+) — Chassis ground (

−−−−

):

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

1 V

Go to step 13.

Replace relay box.

13

CHECK OPEN CIRCUIT IN RELAY CON-
TROL SYSTEM HARNESS.
Measure resistance between VDCCM connec-
tor and relay box connector.

Connector & terminal

(F87) No. 22 — (F90) No. 4:
(F87) No. 10 — (F90) No. 6:

Is the measured value less than the specified 
value?

0.5 

Ω

Go to step 14.

Repair harness 
connector 
between VDCCM 
and relay box.

14

CHECK GROUND SHORT IN HARNESS BE-
TWEEN RELAY BOX AND VDCCM.
Measure resistance between VDCCM connec-
tor and chassis ground.

Connector & terminal

(F87) No. 22 — Chassis ground:
(F87) No. 10 — Chassis ground:

Does the measured value exceed the specified 
value?

1 M

Ω

Go to step 15.

Repair harness 
between VDCCM 
and relay box. 
Check fuse SBF 
holder.

15

CHECK BATTERY SHORT IN HARNESS BE-
TWEEN RELAY BOX AND VDCCM.
Measure voltage between VDCCM connector 
and chassis ground.

Connector & terminal

(F87) No. 10 (+) — Chassis ground (

−−−−

):

Is the measured value less than the specified 
value?

1 V

Go to step 16.

Repair harness 
between VDCCM 
and relay box. 
Check fuse SBF 
holder.

16

CHECK BATTERY SHORT IN HARNESS BE-
TWEEN RELAY BOX AND VDCCM.
1) Turn ignition switch to ON.
2) Measure voltage between VDCCM connec-

tor and chassis ground.

Connector & terminal

(F87) No. 10 (+) — Chassis ground (

−−−−

):

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

1 V

Go to step 17.

Repair harness 
between VDCCM 
and relay box. 
Check fuse SBF 
holder.

17

CHECK POOR CONTACT IN CONNECTORS.
Turn ignition switch to OFF.
Is there poor contact in connector between 
VDCH/U, relay box and VDCCM?

There is poor contact.

Repair connector.

Go to step 18.

18

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 19.

Step

Value

Yes

No

VDC-222

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

19

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

VDC-223

VDC (DIAGNOSTICS)

DIAGNOSTICS CHART WITH SELECT MONITOR

MEMO: