Subaru Legacy 2002 Service Manual page 2634

DIAGNOSTICS CHART WITH SELECT MONITOR
No.
1 CHECK HARNESS/CONNECTOR
BETWEEN VDCCM AND ECM.
1) Turn ignition switch to OFF.
2) Disconnect connector from VDCCM.
3) Disconnect connector from ECM.
4) Measure resistance between VDCCM con-
nector and ECM.
Connector & terminal
H4 ENGINE MODEL
(F87) No. 43 — (B135) No. 5:
H6 ENGINE MODEL
(F87) No. 43 — (B134) No. 4:
2 CHECK GROUND SHORT OF HARNESS.
Measure resistance between VDCCM connec-
tor and chassis ground.
Connector & terminal
(F87) No. 43 — Chassis ground:
3 CHECK BATTERY SHORT OF HARNESS.
Measure voltage between VDCCM connector
and chassis ground.
Connector & terminal
(F87) No. 43 (+) — Chassis ground (−):
4 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. 43 (+) — Chassis ground (−):
5 CHECK HARNESS/CONNECTOR
BETWEEN VDCCM AND ECM.
1) Turn ignition switch to OFF.
2) Connect connector to ECM.
3) Turn ignition switch to ON.
4) Measure voltage between VDCCM connec-
tor and chassis ground.
Connector & terminal
(F87) No. 43 (+) — Chassis ground (−):
6 CHECK POOR CONTACT IN CONNEC-
TORS.
7 CHECK VDCCM.
1) Turn ignition switch to OFF.
2) Connect all connectors.
3) Erase the memory.
4) Perform inspection mode.
5) Read out the diagnostic trouble code.
8 CHECK ANY OTHER DIAGNOSTIC
TROUBLE CODES APPEARANCE.
Step
Is the resistance less than
0.5 Ω?
Is the resistance more than
1 MΩ?
Is the voltage less than 0.5
V?
Is the voltage less than 1
V?
Is the voltage between 10
and 15 V?
Is there poor contact in
connectors between ECM
and VDCCM?
Is the same diagnostic
trouble code as in the cur-
rent diagnosis still being
output?
Are other diagnostic trouble
codes being output?
VDC-175
Check Yes
Go to step 2.
Go to step 3.
Go to step 4.
Go to step 5.
Go to step 6.
Repair connector.
Replace VDCCM.
<Ref. to VDC-9,
VDC Control Mod-
ule (VDCCM).>
Proceed with the
diagnosis corre-
sponding to the
diagnostic trouble
code.
VDC (Diagnostics)
No
Repair harness/
connector
between VDCCM
and ECM.
Repair harness/
connector
between VDCCM
and ECM.
Repair harness/
connector
between VDCCM
and ECM.
Repair harness/
connector
between VDCCM
and ECM.
Go to step 9.
Go to step 7.
Go to step 8.
A temporary poor
contact.