Subaru Legacy 2002 Service Manual page 2544

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR
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. 21 — (B135) No. 6:
(F87) No. 43 — (B135) No. 5:
(F87) No. 8 — (B135) No. 18:
H6 ENGINE MODEL
(F87) No. 21 — (B134) No. 12:
(F87) No. 43 — (B134) No. 4:
(F87) No. 8 — (B134) No. 11:
2 CHECK GROUND SHORT OF HARNESS.
Measure resistance between VDCCM connec-
tor and chassis ground.
Connector & terminal
(F87) No. 21 — Chassis ground:
(F87) No. 43 — Chassis ground:
(F87) No. 8 — Chassis ground:
3 CHECK BATTERY SHORT OF HARNESS.
Measure voltage between VDCCM connector
and chassis ground.
Connector & terminal
(F87) No. 21 (+) — Chassis ground (−):
(F87) No. 43 (+) — Chassis ground (−):
(F87) No. 8 (+) — 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. 21 (+) — Chassis ground (−):
(F87) No. 43 (+) — Chassis ground (−):
(F87) No. 8 (+) — 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. 21 (+) — Chassis ground (−):
(F87) No. 43 (+) — Chassis ground (−):
(F87) No. 8 (+) — 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.
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?
VDC-85
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).>
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.