Page 654 of 2870
IM-12
IMMOBILIZER (DIAGNOSTIC)
Diagnostics Chart for Immobilizer Warning Light
2. CHECK KEY WARNING SWITCH CIRCUIT
WIRING DIAGRAM:
IM-00006
B74
B61
F44
KEY WARNING
SWITCH
B141IMM ECM
LHD
RHDLHD
RHD
BATTERYM/B No.6
4
12
4
B74
1
2
B141
34 12
89
10 11125
67
F44
3
1
56
78
LHD: LHD MODEL
: RHD MODEL
RHD
2
4
Page 655 of 2870

IM-13
IMMOBILIZER (DIAGNOSTIC)
Diagnostics Chart for Immobilizer Warning Light
Step Check Yes No
1 CHECK POWER SUPPLY CIRCUIT.
1) Disconnect the harness connector from key
warning switch.
2) Measure the voltage between key warning
switch harness connector terminal and chassis
ground.
Connector & terminal
(B74) No. 2 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 2.Check the harness
for open or short
between key warn-
ing switch and
fuse.
2 CHECK KEY WARNING SWITCH.
1) Insert the ignition key to the ignition switch.
(OFF or ACC position)
2) Measure the resistance between key warn-
ing switch connector terminals.
Te r m i n a l
No. 1 — No. 2:Is the resistance less than 1
Ω?Go to step 3.Replace the key
warning switch.
3 CHECK KEY WARNING SWITCH.
1) Remove the ignition key from the ignition
switch.
2) Measure the resistance between key warn-
ing switch connector terminals.
Te r m i n a l
No. 1 — No. 2:Is the resistance more than
1 MΩ?Go to step 4.Replace the key
warning switch.
4 CHECK HARNESS BETWEEN KEY WARN-
ING SWITCH AND IMM ECM.
1) Disconnect the harness connector from key
warning switch.
2) Disconnect the harness connector from
IMM ECM.
3) Measure the resistance between key warn-
ing switch harness connector terminal and
IMM ECM harness connector terminal.
Connector & terminal
(B74) No. 1 — (B141) No. 4:Is the resistance less than 10
Ω?Replace the IMM
ECM
37, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
teaching opera-
tion manual (Pub.
No. S0820GZ).Repair the har-
ness between key
warning switch
and IMM ECM.
Page 656 of 2870

IM-14
IMMOBILIZER (DIAGNOSTIC)
List of Diagnostic Trouble Code (DTC)
9. List of Diagnostic Trouble Code (DTC)
A: LIST
NOTE:
Perform the engine DTC when the DTC except immobilizer DTC is detected.
Diagnostic Trouble Code (DTC).>
to EN(H4DOTC 2.5)-65, List of Diagnostic Trouble Code (DTC).>
DTC Item Contents of diagnosis Index No.
P1571Reference Code Incompati-
bilityReference code incompatibility
between IMM ECM and ECM
INCOMPATIBILITY, Diagnostics Procedure with
Diagnostic Trouble Code (DTC).>
P1572EGI — Immobilizer Commu-
nication
(Except Antenna Circuit)Communication failure between
IMM ECM and ECM
URE (EXCEPT ANTENNA CIRCUIT), Diagnostics
Procedure with Diagnostic Trouble Code (DTC).>
P1574Key — Immobilizer Commu-
nicationFailure of IMM ECM to verify key
(transponder) ID code
TION FAILURE, Diagnostics Procedure with Diag-
nostic Trouble Code (DTC).>
P0513 Incorrect Immobilizer Key Incorrect immobilizer key (Use of
unregistered key in IMM ECM)
LIZER KEY, Diagnostics Procedure with Diagnostic
Trouble Code (DTC).>
P1576EGI Control Module
EEPROMECM malfunctioning
ULE EEPROM, Diagnostics Procedure with Diag-
nostic Trouble Code (DTC).>
P1577IMMControl Module
EEPROMIMM ECM malfunctioning
ULE EEPROM, Diagnostics Procedure with Diag-
nostic Trouble Code (DTC).>
P1570 ANTENNA Faulty antenna
Procedure with Diagnostic Trouble Code (DTC).>
Page 657 of 2870
IM-15
IMMOBILIZER (DIAGNOSTIC)
Diagnostics Procedure with Diagnostic Trouble Code (DTC)
10.Diagnostics Procedure with Diagnostic Trouble Code (DTC)
A: DTC P1571 REFERENCE CODE INCOMPATIBILITY
DIAGNOSIS:
Reference code incompatibility between IMM ECM and ECM
Step Check Yes No
1 PERFORM TEACHING OPERATION ON IG-
NITION KEY.
Perform teaching operation on all keys of the
vehicle. Refer to the teaching operation man-
ual.Is teaching operation for all
keys completed?END Replace the ECM
FU(H4SO)-44,
Engine Control
Module (ECM).>
FU(H4DOTC)-50,
Engine Control
Module (ECM).>
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>, IMM
ECM
37, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).
Page 660 of 2870

IM-18
IMMOBILIZER (DIAGNOSTIC)
Diagnostics Procedure with Diagnostic Trouble Code (DTC)
6 CHECK HARNESS OF COMMUNICATION
LINE.
1) Turn the ignition switch to ON. (engine
OFF.)
2) Measure the voltage between IMM ECM
harness connector terminal and chassis
ground.
Connector & terminal
(B141) No. 1, No. 6 (+) — Chassis ground
(
−):Is the voltage 0 V? Go to step 7.Repair the har-
ness between IMM
ECM and ECM,
because there is
short circuit with
battery voltage line
or ignition switch
“ON” line.
7 CHECK HARNESS OF COMMUNICATION
LINE.
Measure the voltage between ECM harness
connector terminal and engine ground.
Connector & terminal
Non-turbo model
(B137) No. 17, No. 18 (+) — Engine
ground(
−):
Turbo model
(B137) No. 19, No. 27 (+) — Engine
ground(
−):Is the voltage 0 V? Go to step 8.Repair the har-
ness between IMM
ECM and ECM,
because there is
short circuit with
battery voltage line
or ignition switch
“ON” line.
8 CHECK ECM BY COMMUNICATION LINE
CHECK.
1) Connect the harness connector to ECM.
2) Disconnect the harness connector from
IMM ECM.
3) Perform communication line check.
IM-7, COMMUNICATION LINE CHECK,
OPERATION, Subaru Select Monitor.>Does “Communication Line not
Shorted” appear on the
screen?Replace the IMM
ECM
37, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).Replace the ECM.
FU(H4SO)-44,
Engine Control
Module (ECM).>
FU(H4DOTC)-50,
Engine Control
Module (ECM).>
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).> Then per-
form teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ). Step Check Yes No
Page 661 of 2870

IM-19
IMMOBILIZER (DIAGNOSTIC)
Diagnostics Procedure with Diagnostic Trouble Code (DTC)
C: DTC P1574 KEY COMMUNICATION FAILURE
DIAGNOSIS:
Failure of IMM ECM to verify key (transponder) ID code
Step Check Yes No
1 CHECK IMM ECM FUNCTION.
Insert the key to ignition switch (LOCK posi-
tion), measure changes in voltage between
Antenna connector.
Connector & terminal
(B142) No. 1 (+) — No. 2: (
−)Is the voltage −30 to 30 V?
(Approx. 0.1 second after
inserting the key)
Is the voltage 0 V?
(Approx. 1 second after insert-
ing the key)Go to step 2.Replace the IMM
ECM
37, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).
2 CHECK IGNITION KEY (TRANSPONDER).
1) Remove the key from ignition switch.
2) Start the engine using other keys that have
undergone the teaching operation, furnished
with vehicle.Does the engine start? Replace the igni-
tion key (including
the transponder).
Then perform
teaching opera-
tion. Refer to the
teaching opera-
tion manual (Pub.
No. S0820GZ).Replace the IMM
ECM
37, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).
Page 662 of 2870

IM-20
IMMOBILIZER (DIAGNOSTIC)
Diagnostics Procedure with Diagnostic Trouble Code (DTC)
D: DTC P0513 INCORRECT IMMOBILIZER KEY
DIAGNOSIS:
Use of unregistered key in IMM ECM
E: DTC P1576 EGI CONTROL MODULE EEPROM
DIAGNOSIS:
ECM malfunctioning
1. REPLACE ECM.
Replace the ECM.
(ECM).>
Then perform teaching operation. Refer to the teaching operation manual (Pub. No. S0820GZ).
F: DTC P1577 IMM CONTROL MODULE EEPROM
DIAGNOSIS:
IMM ECM malfunctioning
1. REPLACE IMM ECM.
Replace the IMM ECM , and then replace all ignition keys (in-
cluding the transponder). Then perform teaching operation. Refer to the teaching operation manual (Pub.
No. S0820GZ).
Step Check Yes No
1 PERFORM TEACHING OPERATION ON IG-
NITION KEY.
Perform teaching operation on all keys of the
vehicle. Refer to the teaching operation man-
ual (Pub. No. S0820GZ).Is teaching operation for all
keys completed?END Replace all ignition
keys (including the
transponder). Go
to step 2.
2 PERFORM TEACHING OPERATION ON IG-
NITION KEY.
Perform teaching operation on all keys with
vehicle. Refer to the teaching operation man-
ual (Pub. No. S0820GZ).Is teaching operation for all
keys completed?END Replace the IMM
ECM
37, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).
Page 664 of 2870

IM-22
IMMOBILIZER (DIAGNOSTIC)
Diagnostics Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK ANTENNA CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the harness antenna connector
from IMM ECM.
Antenna.>
3) Measure the resistance of antenna circuit.
Connector & terminal
(B142) No. 1 — No. 2:Is the resistance less than 10
Ω?Go to step 2.Replace the
antenna.
SL-38, Immobi-
lizer Antenna.>
2 CHECK ANTENNA CIRCUIT.
Measure the resistance between antenna har-
ness connector and chassis ground.
Connector & terminal
(B142) No. 1 — Chassis ground:Is the resistance less than 10
Ω?Replace the
antenna.
SL-38, Immobi-
lizer Antenna.>Go to step 3.
3 CHECK ANTENNA CIRCUIT.
Measure the resistance between antenna har-
ness connector and chassis ground.
Connector & terminal
(B142) No. 2 — Chassis ground:Is the resistance less than 10
Ω?Replace the
antenna.
SL-38, Immobi-
lizer Antenna.>Go to step 4.
4 CHECK ANTENNA CIRCUIT.
1) Turn the ignition switch to ON. (engine
OFF.)
2) Measure the voltage between antenna har-
ness connector and chassis ground.
Connector & terminal
(B142) No. 1 (+) — Chassis ground(
−):Is the voltage 0 V? Go to step 5.Replace the
antenna.
SL-38, Immobi-
lizer Antenna.>
5 CHECK ANTENNA CIRCUIT.
Measure the voltage between antenna har-
ness connector and chassis ground.
Connector & terminal
(B142) No. 2 (+) — Chassis ground(
−):Is the voltage 0 V? Go to step 6.Replace the
antenna.
SL-38, Immobi-
lizer Antenna.>
6 CHECK IMM ECM FUNCTION.
1) Turn the ignition switch to OFF.
2) Connect the 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 (
−):Is the voltage −30 to 30 V?
(Approx. 0.1 second after
inserting the key)
Is the voltage 0 V?
(Approx. 1 second after insert-
ing the key)Go to step 7.Replace the IMM
ECM
37, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).
7 CHECK IGNITION KEY (TRANSPONDER).
1) Remove the key from ignition switch.
2) Start the engine using other keys that have
undergone the teaching operation, furnished
with vehicle.Does the engine start? Replace the igni-
tion key (including
the transponder).
Then perform
teaching opera-
tion. Refer to the
teaching opera-
tion manual (Pub.
No. S0820GZ).Replace the IMM
ECM
37, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).