Subaru Legacy 2003 Service Manual page 4046

DIAGNOSTIC PROCEDURE WITH TROUBLE CODE (DTC)
Step
5 CHECK HARNESS BETWEEN IMM ECM
AND ECM.
Measure resistance between IMM ECM har-
ness connector terminal and ECM harness
connector terminal.
Connector & terminal
H4 non-TURBO without OBD model
(B141) No. 6 — (B135) No. 23:
H4 non-TURBO with OBD model
(B141) No. 6 — (B137) No. 17:
H6 and H4 TURBO models
(B141) No. 6 — (B135) No. 14:
Is the measured value less than the specified
value?
6 CHECK HARNESS OF COMMUNICATION
LINE.
1) Turn ignition switch ON. (Engine OFF.)
2) Measure voltage between IMM ECM har-
ness connector terminal and chassis
ground.
Connector & terminal
(B141) No. 1, No.6 (+) — Chassis
ground ( − − − − ):
Is the measured value same as the speci-
fied value?
7 CHECK HARNESS OF COMMUNICATION
LINE.
Measure voltage between ECM harness con-
nector terminal and chassis ground.
Connector & terminal
H4 non-TURBO without OBD model
(B135) No. 22, No.23 (+) — Chassis
ground ( − − − − ):
H4 non-TURBO with OBD model
(B137) No. 17, No.18 (+) — Chassis
ground ( − − − − ):
H6 and H4 TURBO models
(B135) No. 5, No.14 (+) — Chassis
ground ( − − − − ):
Is the measured value same as the specified
value?
Value
10 Ω
0 V
0 V
IM-21
IMMOBILIZER (DIAGNOSTICS)
Yes
Go to step 6. Repair open circuit
of harness
between IMM
ECM and ECM.
Go to step 7. Repair harness
between IMM
ECM and ECM,
because there is
short circuit in bat-
tery voltage line or
ignition switch
"ON" line.
Go to step 8. Repair harness
between IMM
ECM and ECM,
because there is
short circuit in bat-
tery voltage line or
ignition switch
"ON" line.
No