Subaru Legacy 2004 Service Manual page 4067

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK ANTENNA CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the harness connector from
antenna. <Ref. to SL-50, Immobilizer
Antenna.>
3) Measure the resistance of antenna circuit.
Connector & terminal
(B351) No. 1 — No. 2:
2 CHECK ANTENNA CIRCUIT.
1) Disconnect the harness connector from
body integrated unit.
2) Measure the resistance between harness
connector and chassis ground.
Connector & terminal
(B281) No. 21 — Chassis ground:
3 CHECK ANTENNA CIRCUIT.
Measure the resistance between harness con-
nector and chassis ground.
Connector & terminal
(B281) No. 20 — Chassis ground:
4 CHECK ANTENNA CIRCUIT.
1) Turn the ignition switch to ON. (engine
OFF)
2) Measure the voltage between harness con-
nector and chassis ground.
Connector & terminal
(B281) No. 21 (+) — Chassis ground (
5 CHECK ANTENNA CIRCUIT.
Measure the voltage between harness connec-
tor and chassis ground.
Connector & terminal
(B281) No. 20 (+) — Chassis ground (
6 CHECK BODY INTEGRATED UNIT FUNC-
TION.
1) Turn the ignition switch to OFF.
2) Connect the harness connector to body
integrated unit.
3) Insert the key to ignition switch, and mea-
sure the changes in voltage between antenna
harness connectors.
Connector & terminal
(B281) No. 20 (+) — No. 21 (
Is the resistance less than 10
"?
Is the resistance less than 10
"?
Is the resistance less than 10
"?
Is the voltage 0 V?
#
):
Is the voltage 0 V?
#
):
Is the voltage #30 to 30 V?
(Approx. 0.1 second after
inserting the key) Is the voltage
0 V? (Approx. 1 second after
inserting the key)
#
):
IM(diag)-19
IMMOBILIZER (DIAGNOSTICS)
Check Yes
Go to step 2.
Repair the har-
ness.
Repair the har-
ness.
Go to step 5.
Go to step 6.
Go to step 7.
No
Replace the
antenna. <Ref. to
SL-50, Immobi-
lizer Antenna.>
Go to step 3.
Go to step 4.
Repair the har-
ness.
Repair the har-
ness between
body integrated
unit and antenna,
because there is
short circuit with
battery voltage line
or ignition switch
"ON" line.
Replace the body
integrated unit
<Ref. to SL-46,
Body Integrated
Unit.> and replace
all the ignition keys
(including tran-
sponder). Execute
the registration
procedure next.
Refer to "REGIS-
TRATION MAN-
UAL FOR
IMMOBILIZER".