Subaru Legacy IV (2008 year). Manual - part 1164

IM(diag)-13

Diagnostics Chart for Security Indicator Light

IMMOBILIZER (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK POWER SUPPLY CIRCUIT.
1) Disconnect the key warning switch harness 
connector.
2) Turn the ignition switch to “ACC” or “LOCK” 
(with key inserted).
3) Measure the voltage between key warning 
switch harness connector terminal and chassis 
ground.

Connector & terminal

(B350) No. 3 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step 2.

Check the harness 
for an open or 
short between the 
key warning switch 
and fuse.

2

CHECK KEY WARNING SWITCH.
1) Insert the ignition key in the ignition switch. 
(OFF or ACC)
2) Measure the resistance between key warn-
ing switch connector terminals.

Connector & terminal

No. 3 — No. 4:

Is the resistance less than 1 

:? Go to step 3.

Replace the key 
warning switch.

3

CHECK KEY WARNING SWITCH.
1) Remove the ignition key from ignition 
switch.
2) Measure the resistance between key warn-
ing switch connector terminals.

Connector & terminal

No. 3 — No. 4:

Is the resistance 1 M

: or 

more?

Go to step 4.

Replace the key 
warning switch.

4

CHECK HARNESS BETWEEN KEY WARN-
ING SWITCH AND BODY INTEGRATED 
UNIT.
1) Disconnect the key warning switch harness 
connector.
2) Disconnect the harness connector from 
body integrated unit.
3) Measure the resistance between key warn-
ing switch harness connector terminal and body 
integrated unit harness connector terminal.

Connector & terminal

(B350) No. 4 — (B281) No. 7:

Is the resistance less than 10 

:? Replace the body 

integrated unit 
<Ref. to SL-56, 
Body Integrated 
Unit.> Replace all 
ignition keys 
(including the tran-
sponder). Execute 
the registration 
procedure next. 
Refer to the “PC 
application help for 
Subaru Select 
Monitor”.

Repair the harness 
between key warn-
ing switch and 
body integrated 
unit.

IM(diag)-14

List of Diagnostic Trouble Code (DTC)

IMMOBILIZER (DIAGNOSTICS)

9. List of Diagnostic Trouble Code (DTC)

A: LIST

1. ECM

NOTE:
Perform diagnosis of engine DTC when a DTC other than an immobilizer DTC is detected. <Ref. to
EN(H4DOTC)(diag)-81, List of Diagnostic Trouble Code (DTC).> <Ref. to EN(H6DO)(diag)-81, List of Diag-
nostic Trouble Code (DTC).>

DTC

Item

Contents of diagnosis

Index No.

P0513

Incorrect Immobilizer Key

Incorrect immobilizer key (Use of 
unregistered key in body integrated 
unit)

<Ref. to IM(diag)-16, DTC P0513 INCORRECT 
IMMOBILIZER KEY, Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).>

P1570

Antenna

Faulty antenna

<Ref. to IM(diag)-17, DTC P1570 ANTENNA, 
Diagnostic Procedure with Diagnostic Trouble 
Code (DTC).>

P1571

Reference Code Incompatibility

Reference code incompatibility 
between body integrated unit and 
ECM

<Ref. to IM(diag)-19, DTC P1571 REFERENCE 
CODE INCOMPATIBILITY, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P1572

IMM Circuit Failure
(Except Antenna Circuit)

Communication failure between 
body integrated unit and ECM

<Ref. to IM(diag)-20, DTC P1572 IMM CIRCUIT 
FAILURE (EXCEPT ANTENNA CIRCUIT), 
Diagnostic Procedure with Diagnostic Trouble 
Code (DTC).>

P1574

Key Communication Failure

Communication failure between key 
and body integrated unit

<Ref. to IM(diag)-23, DTC P1574 KEY COM-
MUNICATION FAILURE, Diagnostic Procedure 
with Diagnostic Trouble Code (DTC).>

P1576

EGI Control Module EEPROM

ECM malfunctioning

<Ref. to IM(diag)-23, DTC P1576 EGI CON-
TROL MODULE EEPROM, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P1577

IMM Control Module EEPROM

Body integrated unit malfunctioning

<Ref. to IM(diag)-24, DTC P1577 IMM CON-
TROL MODULE EEPROM, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

P1578

Meter Failure

• Reference code incompatibility 
between combination meter and 
body integrated unit
• Communication failure between 
body integrated unit and ECM

<Ref. to IM(diag)-24, DTC P1578 METER FAIL-
URE, Diagnostic Procedure with Diagnostic 
Trouble Code (DTC).>

IM(diag)-15

List of Diagnostic Trouble Code (DTC)

IMMOBILIZER (DIAGNOSTICS)

2. BODY INTEGRATED UNIT

NOTE:
The starter relay control is performed in immobilizer system. When the body integrated unit detect the incon-
formity of reference code, immediately output the starter relay cut signal to ECM, and then ECM stop the
starter relay operation. In this case, engine does not start, and DTC is not recorded in ECM. Check that the
engine does not start on the DTC of body integrated unit.

DTC

Item

Contents of diagnosis

Index No.

Relation between 

ECM and DTC

B1401

M collation NG

Reference code incompatibility 
between combination meter 
and body integrated unit

<Ref. to IM(diag)-24, DTC P1578 METER 
FAILURE, Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).>

P1578

B1402

Immobirizer Key 
collation NG

• Incorrect immobilizer key 
(Use of unregistered key in 
body integrated unit)
• Faulty antenna

<Ref. to IM(diag)-16, DTC P0513 INCOR-
RECT IMMOBILIZER KEY, Diagnostic 
Procedure with Diagnostic Trouble Code 
(DTC).> <Ref. to IM(diag)-17, DTC P1570 
ANTENNA, Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).> or <Ref. 
to IM(diag)-23, DTC P1574 KEY COMMU-
NICATION FAILURE, Diagnostic Proce-
dure with Diagnostic Trouble Code 
(DTC).>

• P0513
• P1570
• P1574

B1403

E/G request NG

Communication failure 
between body integrated unit 
and ECM

<Ref. to IM(diag)-20, DTC P1572 IMM 
CIRCUIT FAILURE (EXCEPT ANTENNA 
CIRCUIT), Diagnostic Procedure with 
Diagnostic Trouble Code (DTC).>

P1572

IM(diag)-16

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

IMMOBILIZER (DIAGNOSTICS)

10.Diagnostic Procedure with Diagnostic Trouble Code (DTC)

A: DTC P0513 INCORRECT IMMOBILIZER KEY

DTC DETECTING CONDITION:
Incorrect immobilizer key (Use of unregistered key in body integrated unit)

Step

Check

Yes

No

1

PERFORM REGISTRATION ON IGNITION 
KEY.
Perform registration on all keys of the vehicle. 
Refer to the “PC application help for Subaru 
Select Monitor”.

Is registration for all keys com-
plete?

END

Replace ignition 
keys (including 
transponder) 
which cannot be 
registered. Go to 
step 2.

2

PERFORM REGISTRATION ON IGNITION 
KEY.
Perform registration on all keys of the vehicle. 
Refer to the “PC application help for Subaru 
Select Monitor”.

Is registration for all keys com-
plete?

END

Replace the body 
integrated unit 
<Ref. to SL-56, 
Body Integrated 
Unit.> Replace all 
ignition keys 
(including the tran-
sponder). Execute 
the registration 
procedure next. 
Refer to the “PC 
application help for 
Subaru Select 
Monitor”.