Subaru Legacy (2005 year). Manual - part 1028

IM(diag)-17

IMMOBILIZER (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

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 module)

Step

Check

Yes

No

1

PERFORM TEACHING OPERATION ON IG-
NITION KEY.
Perform teaching operation on all keys of the 
vehicle. Refer to “IMMOBILIZER TEACHING 
OPERATION MANUAL”.

Is the teaching operation for all 
keys completed?

Finish the diagno-
sis.

Replace the igni-
tion keys (includ-
ing transponder) 
which cannot be 
registered. Go to 
step 2.

2

PERFORM TEACHING OPERATION ON IG-
NITION KEY.
Perform teaching operation on all keys of the 
vehicle. Refer to “IMMOBILIZER TEACHING 
OPERATION MANUAL”.

Is the teaching operation for all 
keys completed?

Finish the diagno-
sis.

Replace the body 
integrated module 
<Ref. to SL-44, 
Body Integrated 
Module.> and 
replace all the igni-
tion keys (includ-
ing transponder). 
Execute the regis-
tration procedure 
next. Refer to 
“IMMOBILIZER 
TEACHING 
OPERATION 
MANUAL”.

IM(diag)-18

IMMOBILIZER (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

B: DTC P1570 ANTENNA

DTC DETECTING CONDITION:
Faulty antenna
WIRING DIAGRAM:

IM-00079

C20

C21

ANTENNA

B351

1 2

2

1

B281

BODY INTEGRATED

MODULE

C:

B351

5 6 7

8

2

1

9

4

3

10

24

22 23

25

11 12 13 14 15

26

27 28

16 17 18 19

20 21

B281

C:

IM(diag)-19

IMMOBILIZER (DIAGNOSTICS)

Diagnostic 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 connector from 
antenna. <Ref. to SL-48, Immobilizer 
Antenna.>
3) Measure the resistance of antenna circuit.

Connector & terminal

(B351) No. 1 — No. 2:

Is the resistance less than 10 
Ω?

Go to step 2.

Replace the 
antenna. <Ref. to 
SL-48, Immobi-
lizer Antenna.>

2

CHECK ANTENNA CIRCUIT.
1) Disconnect the harness connector from 
body integrated module.
2) Measure the resistance between harness 
connector and chassis ground.

Connector & terminal

(B281) No. 21 — Chassis ground:

Is the resistance less than 10 
Ω?

Repair the har-
ness. 

Go to step 3.

3

CHECK ANTENNA CIRCUIT.
Measure the resistance between harness con-
nector and chassis ground.

Connector & terminal

(B281) No. 20 — Chassis ground:

Is the resistance less than 10 
Ω?

Repair the har-
ness.

Go to step 4.

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 (

−

):

Is the voltage 0 V?

Go to step 5.

Repair the har-
ness. 

5

CHECK ANTENNA CIRCUIT.
Measure the voltage between harness connec-
tor and chassis ground.

Connector & terminal

(B281) No. 20 (+) — Chassis ground (

−

):

Is the voltage 0 V?

Go to step 6.

Repair the har-
ness between 
body integrated 
module and 
antenna, because 
there is short cir-
cuit with battery 
voltage line or igni-
tion switch “ON” 
line.

6

CHECK BODY INTEGRATED MODULE 
FUNCTION.
1) Turn the ignition switch to OFF.
2) Connect the harness connector to body 
integrated module.
3) Insert the key to ignition switch, and mea-
sure the changes in voltage between antenna 
harness connectors.

Connector & terminal

(B281) No. 20 (+) — Chassis ground (

−

):

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)

Go to step 7.

Replace the body 
integrated module 
<Ref. to SL-44, 
Body Integrated 
Module.> and 
replace all the igni-
tion keys (includ-
ing transponder). 
Execute the regis-
tration procedure 
next. Refer to 
“IMMOBILIZER 
TEACHING 
OPERATION 
MANUAL”.

IM(diag)-20

IMMOBILIZER (DIAGNOSTICS)

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

C: DTC P1571 REFERENCE CODE INCOMPATIBILITY

DTC DETECTING CONDITION:
Reference code incompatibility between body integrated module and ECM

7

CHECK IGNITION KEY (TRANSPONDER).
1) Remove the key from ignition switch.
2) Start the engine using other key which is 
already registered.

Does the engine start?

Replace all the 
ignition keys 
(including tran-
sponder). Execute 
the registration 
procedure next. 
Refer to “IMMOBI-
LIZER TEACH-
ING OPERATION 
MANUAL”.

Replace the body 
integrated module 
<Ref. to SL-44, 
Body Integrated 
Module.> and 
replace all the igni-
tion keys (includ-
ing transponder). 
Execute the regis-
tration procedure 
next. Refer to 
“IMMOBILIZER 
TEACHING 
OPERATION 
MANUAL”.

Step

Check

Yes

No

1

PERFORM TEACHING OPERATION ON IG-
NITION KEY.
Perform teaching operation on all keys of the 
vehicle. Refer to “IMMOBILIZER TEACHING 
OPERATION MANUAL”.

Is the teaching operation for all 
keys completed?

Finish the diagno-
sis.

Replace the ECM. 
<Ref. to FU(H4SO 
2.0)-34, Engine 
Control Module 
(ECM).> <Ref. to 
FU(H4SO 2.5)-37, 
Engine Control 
Module (ECM).> 
<Ref. to 
FU(H4DOTC)-34, 
Engine Control 
Module (ECM).> 
<Ref. to 
FU(H6DO)-34, 
Engine Control 
Module (ECM).> 
Replace the body 
integrated module 
<Ref. to SL-44, 
Body Integrated 
Module.> and 
replace all the igni-
tion keys (includ-
ing transponder). 
Execute the regis-
tration procedure 
next. Refer to 
“IMMOBILIZER 
TEACHING 
OPERATION 
MANUAL”.

Step

Check

Yes

No