Subaru LEGACY 2003 Service Manual page 81

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR
Step
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 RHD without OBD model
(F87) No. 21 — (B136) No. 7:
(F87) No. 43 — (B136) No. 8:
(F87) No. 8 — (B136) No. 2:
H4 engine RHD with OBD model
(F87) No. 21 — (B135) No. 6:
(F87) No. 43 — (B135) No. 5:
(F87) No. 8 — (B135) No. 18:
H4 engine LHD model
(F87) No. 21 — (B136) No. 7:
(F87) No. 43 — (B136) No. 8:
(F87) No. 8 — (B136) No. 2:
H6 engine model
(F87) No. 21 — (B134) No. 12:
(F87) No. 43 — (B134) No. 4:
(F87) No. 8 — (B134) No. 11:
Is the measured value less than the speci-
fied value?
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:
Does the measured value exceed the specified
value?
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 ( − − − − ):
Is the measured value less than the specified
value?
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 ( − − − − ):
Is the measured value less than the speci-
fied value?
Value
0.5 Ω
1 MΩ
0.5 V
1 V
VDC-79
VDC (DIAGNOSTICS)
Yes
Go to step 2. Repair harness/
connector
between VDCCM
and ECM.
Go to step 3. Repair harness/
connector
between VDCCM
and ECM.
Go to step 4. Repair harness/
connector
between VDCCM
and ECM.
Go to step 5. Repair harness/
connector
between VDCCM
and ECM.
No