Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 769

IM(diag)-11

Diagnostics Chart for Security Indicator Light

IMMOBILIZER (DIAGNOSTICS)

8. Diagnostics Chart for Security Indicator Light

A: INSPECTION

1. CHECK SECURITY INDICATOR LIGHT CIRCUIT

WIRING DIAGRAM:

Immobilizer system <Ref. to WI-158, WIRING DIAGRAM, Immobilizer System.>

Step

Check

Yes

No

1

CHECK FUSE.
1) Remove the ignition key from ignition
switch.
2) Check the fuse (M/B No. 8).

Is the fuse OK?

Go to step

2.

Replace the fuse. If
the replaced fuse
blows out easily,
repair the short cir-
cuit in the harness
between the fuse
and body inte-
grated unit.

2 3 4 5

1

6 7 8

i97

1

*

i97

1

*

1

*

B225

13
14

15 16

17

27

24

25
26

20

21
22

23

29
30

31

28

32 35

33
34

37
38

39

36

40

8

9

10

11 12

1

2

5

3

4

7

6

19

18

3

4

10A

B225

B6

i10

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

B: B280

5

4

6

7 8

2

1

9

3

0

1

22 23

1

1

2

1

3

1

4

1

5

1

24

25 26

6

1

7

1

8

1

9

1

0

2

1

2

A2

8

D: B279

IM-00378

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

i102

i102

R167

2

D:

C:

A:

B279

30

21

20

19
29

28

18

17

16

27

26

25

24

15

14

13

12

11
23

22

10

3

9

1 2
8

7

6

4 5

35

34

33

32

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

i84

B281

21

20

19

18

17

16

28

27

26

15

14

13

12

11

25

23

22

24

10

3

4

9

1 2
8

7

6

5

C: B281

B: B280

A:

i84

D27

1

39

B17

C20

C2

A10

i10

E

E

E

SBF-8

MAIN SBF

BATTERY

COMBINATION

METER

BODY INTEGRATED

UNIT

M/B No. 8

FUSE

(RELAY

BLOCK)

SECURITY/

IMMOBILIZER

INDICATOR

LIGHT

RELAY BLOCK

JOINT GR

OUND

CONNECT

OR

: TERMINAL No. OPTIONAL

ARRANGEMENT

F/B No. 7

IM(diag)-12

Diagnostics Chart for Security Indicator Light

IMMOBILIZER (DIAGNOSTICS)

2

CHECK SECURITY INDICATOR LIGHT.
1) Disconnect the connector from body inte-
grated unit.
2) Connect the resistor (100 Ω) between the
body integrated unit connector terminal (i84)
No. 10 and chassis ground.

Does the security indicator light
illuminate?

Go to step

3.

Go to step

5.

3

CHECK BODY INTEGRATED UNIT GROUND
CIRCUIT.
Measure the resistance between the body inte-
grated unit connector terminal and chassis
ground.

Connector & terminal

(i84) No. 28 — Chassis ground:
(B280) No. 17 — Chassis ground:
(B281) No. 20 — Chassis ground:
(B279) No. 27 — Chassis ground:

Is the resistance less than 10

Ω?

Go to step

4.

Repair the open
circuit of the body
integrated unit
ground circuit.

4

CHECK BODY INTEGRATED UNIT POWER
SUPPLY CIRCUIT.
Measure the voltage between the body inte-
grated unit connector terminal and chassis
ground.

Connector & terminal

(B280) No. 6 (+) — Chassis ground (–):
(B281) No. 2 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Replace the body
integrated unit.
<Ref. to SL-48,
Body Integrated
Unit.> Register all
ignition keys (tran-
sponders). Refer to
the “REGISTRA-
TION MANUAL
FOR IMMOBI-
LIZER”.

Check the harness
for open or short
circuit between
body integrated
unit and fuse.

5

CHECK COMBINATION METER CIRCUIT.
1) Remove the combination meter. <Ref. to
IDI-16, Combination Meter.>
2) Measure the voltage between combination
meter connector terminal and chassis ground.

Connector & terminal

(i10) No. 1 (+) — Chassis ground (–):

Is the voltage 10 V or more?

Go to step

6.

Check for an open
or short circuit in
the harness
between the com-
bination meter and
fuse.

6

CHECK COMBINATION METER CIRCUIT.
Measure the resistance between the body inte-
grated unit connector terminal and combination
meter connector terminal.

Connector & terminal

(i84) No. 10 — (i10) No. 39:

Is the resistance less than 10

Ω?

LED bulb is defec-
tive. Replace the
combination meter
case assembly.
<Ref. to IDI-16,
DISASSEMBLY,
Combination
Meter.>

Repair the harness
or connector.

Step

Check

Yes

No

IM(diag)-13

Diagnostics Chart for Security Indicator Light

IMMOBILIZER (DIAGNOSTICS)

2. CHECK KEY SWITCH CIRCUIT

WIRING DIAGRAM:

Immobilizer system <Ref. to WI-158, WIRING DIAGRAM, Immobilizer System.>

Step

Check

Yes

No

1

CHECK POWER SUPPLY CIRCUIT.
1) Disconnect the connector from key warning
switch.
2) Measure the voltage between key warning
switch 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 Ω? 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 MΩ 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 connector from body inte-
grated unit.
2) Measure the resistance between key warn-
ing switch connector terminal and body inte-
grated unit connector terminal.

Connector & terminal

(B350) No. 4 — (B279) No. 2:

Is the resistance less than 10

Ω?

Replace the body
integrated unit.
<Ref. to SL-48,
Body Integrated
Unit.> Register all
ignition keys (tran-
sponders). Refer to
the “REGISTRA-
TION MANUAL
FOR IMMOBI-
LIZER”.

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

IM-00278

B350

M/B No.14

D2

3

4

B350

1 2 3 4

5

4

6 7

2
9

3

10

22

23

11 12 13 14 15

24 25

26 27

16 17 18

28 29

19 20

21

30

B279

D:

B279

D:

1
8

BATTERY

KEY WARNING

SWITCH

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)-87, List of Diagnostic Trouble Code (DTC).>

2. BODY INTEGRATED UNIT

NOTE:

The starter relay control is performed in immobilizer system. When the body integrated unit detects a non-

conformity of reference code, it immediately outputs a starter relay cut signal to ECM, and then ECM stops

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.

B1570 Antenna

Faulty antenna

<Ref. to IM(diag)-15, DTC B1570 ANTENNA,
Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>

B1571 Reference Code Incompatibility

Reference code incompatibility
between body integrated unit and
ECM

<Ref. to IM(diag)-17, DTC B1571 REFERENCE
CODE INCOMPATIBILITY, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

B1572

IMM Circuit Failure
(Except Antenna Circuit)

Communication failure between
body integrated unit and ECM

<Ref. to IM(diag)-18, DTC B1572 IMM CIRCUIT
FAILURE (EXCEPT ANTENNA CIRCUIT),
Diagnostic Procedure with Diagnostic Trouble
Code (DTC).>

B1574 Key Communication Failure

Communication failure between key
and body integrated unit

<Ref. to IM(diag)-21, DTC B1574 KEY COM-
MUNICATION FAILURE, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>

B1575 Incorrect Immobilizer Key

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

<Ref. to IM(diag)-22, DTC B1575 INCORRECT
IMMOBILIZER KEY, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>

B1576 EGI Control Module EEPROM

ECM malfunctioning

<Ref. to IM(diag)-23, DTC B1576 EGI CON-
TROL MODULE EEPROM, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

B1577 IMM Control Module EEPROM

Body integrated unit malfunctioning

<Ref. to IM(diag)-24, DTC B1577 IMM CON-
TROL MODULE EEPROM, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>

B1578 Meter Failure

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

<Ref. to IM(diag)-25, DTC B1578 METER FAIL-
URE, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>

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)-25, DTC B1401 M COL-
LATION NG, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>

B1578

B1402

Immobilizer Key
Collation NG

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

<Ref. to IM(diag)-25, DTC B1402 IMMO-
BILIZER KEY COLLATION NG, Diagnos-
tic Procedure with Diagnostic Trouble
Code (DTC).>

• B1575
• B1570
• B1574

B1403 E/G Request NG

Communication failure
between body integrated unit
and ECM

<Ref. to IM(diag)-25, DTC B1403 E/G
REQUEST NG, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>

B1572