Subaru Legacy 2002 Service Manual page 3367

DIAGNOSTICS CHART WITH TROUBLE CODE (DTC)
Immobilizer (Diagnostics)
No.
1 CHECK ANTENNA CIRCUIT.
1) Turn ignition switch OFF.
2) Disconnect harness antenna connector
from IMM ECM. <Ref. to SL-36, Immobilizer
Antenna.>
3) Measure resistance of antenna circuit.
Connector & terminal
(B142) No. 1 — No. 2:
2 CHECK ANTENNA CIRCUIT.
Measure resistance between antenna harness
connector and chassis ground.
Connector & terminal
(B142) No. 1 (+) — Chassis ground (−):
3 CHECK ANTENNA CIRCUIT.
Measure resistance between antenna harness
connector and chassis ground.
Connector & terminal
(B142) No. 2 (+) — Chassis ground (−):
4 CHECK ANTENNA CIRCUIT.
1) Turn ignition switch ON. (Engine OFF.)
2) Measure voltage between antenna harness
connector and chassis ground.
Connector & terminal
(B142) No. 1 (+) — Chassis ground (−):
5 CHECK ANTENNA CIRCUIT.
Measure voltage between antenna harness
connector and chassis ground.
Connector & terminal
(B142) No. 2 (+) — Chassis ground (−):
6 CHECK IMM ECM FUNCTION.
1) Turn ignition switch OFF.
2) Connect antenna harness connector to
IMM ECM.
3) Insert the key to ignition switch, measure
changes in voltage between antenna harness
connector.
Connector & terminal
(B142) No. 1 — No. 2:
7 CHECK IGNITION KEY (TRANSPONDER).
1) Remove key from ignition switch.
2) Start engine using other keys that have
undergone the teaching operation, furnished
with vehicle.
Step
Is the resistance less than
10 Ω?
Is the resistance less than
10 Ω?
Is the resistance less than
10 Ω?
Is the voltage 0 V?
Is the voltage 0 V?
Is the voltage −30 to 30 V?
(Approximately 0.1 second
after inserting the key.) Is
the voltage 0 V? (Approxi-
mately 1 second after
inserting the key.)
Does engine start?
IM-22
Check Yes
Go to step 2.
Replace antenna.
<Ref. to SL-36,
Immobilizer
Antenna.>
Replace antenna.
<Ref. to SL-36,
Immobilizer
Antenna.>
Go to step 5.
Go to step 6.
Go to step 7.
Replace ignition
key (including the
transponder).
Then perform
teaching opera-
tion. Refer to
teaching operation
manual (Pub. No.
S0820GZ).
No
Replace antenna.
<Ref. to SL-36,
Immobilizer
Antenna.>
Go to step 3.
Go to step 4.
Replace antenna.
<Ref. to SL-36,
Immobilizer
Antenna.>
Repair harness
between IMM
ECM and
antenna, because
there is short cir-
cuit in battery volt-
age line or ignition
switch "ON" line.
Replace IMM
ECM <Ref. to
SL-35, Immobi-
lizer Control Mod-
ule.> and then
replace all ignition
keys (including
the transponder).
Then perform
teaching opera-
tion. Refer to
teaching operation
manual (Pub. No.
S0820GZ).
Replace IMM
ECM <Ref. to
SL-35, Immobi-
lizer Control Mod-
ule.> and then
replace all ignition
keys (including
the transponder).
Then perform
teaching opera-
tion. Refer to
teaching operation
manual (Pub. No.
S0820GZ).