Subaru LEGACY 2004 Service Manual page 712

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
IMMOBILIZER (DIAGNOSTICS)
Step
6 CHECK HARNESS OF COMMUNICATION
LINE.
1) Turn the ignition switch to ON. (engine
OFF)
2) Measure the voltage between body inte-
grated unit harness connector terminal and
chassis ground.
Connector & terminal
(B280) No. 18, No. 28 (+) — Chassis
#
ground ( ):
7 CHECK HARNESS OF COMMUNICATION
LINE.
Measure the voltage between harness connec-
tor terminal and engine ground.
Connector & terminal
2.0 L non-turbo model, 2.5 L KS, KA
model
(B135) No. 25, 33 (+) — Engine ground
#
( ):
2.0 L turbo model, 3.0 L model, 2.5 L EC,
K4, EK model
(B137) No. 19, 27 (+) — Engine ground
#
( ):
8 CHECK ECM BY COMMUNICATION LINE
CHECK.
1) Connect the harness connector to ECM.
2) Disconnect the harness connector from
body integrated unit.
3) Start the communication line check. <Ref.
to IM(diag)-8, COMMUNICATION LINE
CHECK, OPERATION, Subaru Select Moni-
tor.>
Check
Is the voltage 0 V?
Is the voltage 0 V?
Does "Communication Line not
Shorted" appear on the
screen?
IM(diag)-24
Yes
Go to step 7. Repair the har-
ness between
body integrated
unit and ECM,
because there is
short circuit with
battery voltage line
or ignition switch
"ON" line.
Go to step 8. Repair the har-
ness between
body integrated
unit and ECM,
because there is
short circuit with
battery voltage line
or ignition switch
"ON" line.
Replace the body Replace the ECM.
integrated unit <Ref. to FU(H4SO
<Ref. to SL-46, 2.0)-34, Engine
Body Integrated Control Module
Unit.> and replace (ECM).> <Ref. to
the all ignition keys FU(H4SO 2.5)-36,
(including tran- Engine Control
sponder). Execute Module (ECM).>
the registration <Ref. to
procedure next. FU(H4DOTC)-35,
Refer to "REGIS- Engine Control
TRATION MAN- Module (ECM).>
UAL FOR <Ref. to
IMMOBILIZER". FU(H6DO)-34,
Engine Control
Module (ECM).>
Perform the regis-
tration procedure
next. Refer to
"REGISTRATION
MANUAL FOR
IMMOBILIZER".
No