Isuzu KB P190. Manual — part 1484

11A-38 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)

B0004 IMMOBILIZER COIL CIRCUIT (ANTENNA COIL FAULT)

Step Action Value(s)

Yes

No

1

Was the "Immobilizer System Check" performed?



Go to Step 2

Go to Immobilizer

System Check

2

Check the immobilizer coil (antenna) circuit.

1. Key position is “OFF”.

2. Disconnect the immobilizer control unit (ICU).

(immobilizer coil circuit : 3 pin connector)

3. Check the immobilizer coil circuit for an open, short

to ground, or short to voltage.

Also, check the ICU ignition feed circuit for an open or
short to ground and the ICU ground circuit for an
open.

Was a problem found?



Go to Step 3

Go to Step 4

3

Repair or replace the immobilizer coil (antenna).

Was the action complete?



Verify repair



4

Recheck the DTC.

1. Key position is “OFF” and keep the position for

more than 30 seconds.

2. Key position is “ON”.

3. Check the DTC on scan tool.

Is DTC B0004 stored?



Go to Step 5

Verify repair

5

Replace the immobilizer control unit (ICU).

IMPORTANT: The replacement ICU must be
programmed the security data by scan tool.

Was the action complete?



Verify repair



IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-39

B0005 COMMUNICATION LINE W VOLTAGE LOW

Step Action Value(s)

Yes

No

1

Was the "Immobilizer System Check" performed?



Go to Step 2

Go to Immobilizer

System Check

2

Recheck the DTC.

1. Key position is “OFF”.

2. Install the scan tool on vehicle.

3. Key position is “ON”.

4. Check the DTC on scan tool.

Is DTC B0005 stored?



Go to Step 3

Refer to

Diagnostic Aids

3

Check the immobilizer communication W line circuit.

1. Key position is “OFF”.

2. Disconnect the immobilizer control unit (ICU).

3. Disconnect the engine control module (ECM).

4. Check the immobilizer communication W line

circuit for an open, short to ground, or short to

voltage.

Also, check the ICU and ECM ignition feed circuits for
an open or short to ground and the ICU and ECM
ground circuit for an open.

Was a problem found?



Go to Step 4

Go to Step 5

4

Repair or replace the immobilizer communication W
line circuit.

Was the action complete?



Verify repair



5

Replace the immobilizer control unit (ICU).

IMPORTANT: The replacement ICU must be
programmed the security data by scan tool.

Was the action complete?



Verify repair



11A-40 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)

B0006 COMMUNICATION LINE W VOLTAGE HIGH

Step Action Value(s)

Yes

No

1

Was the "Immobilizer System Check" performed?



Go to Step 2

Go to Immobilizer

System Check

2

Recheck the DTC.

1. Key position is “OFF”.

2. Install the scan tool on vehicle.

3. Key position is “ON”.

4. Check the DTC on scan tool.

Is DTC B0006 stored?



Go to Step 3

Refer to

Diagnostic Aids

3

Check the immobilizer communication W line circuit.

1. Key position is “OFF”.

2. Disconnect the immobilizer control unit (ICU).

3. Disconnect the engine control module (ECM).

4. Check the immobilizer communication W line

circuit for an open, short to ground, or short to

voltage.

Also, check the ICU and ECM ignition feed circuits for
an open or short to ground and the ICU and ECM
ground circuit for an open.

Was a problem found?



Go to Step 4

Go to Step 5

4

Repair or replace the immobilizer communication W
line circuit.

Was the action complete?



Verify repair



5

Replace the immobilizer control unit (ICU).

IMPORTANT: The replacement ICU must be
programmed the security data by scan tool.

Was the action complete?



Verify repair



IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-41

B0007 NO ENGINE REQUEST RECEIVED

Step Action Value(s)

Yes

No

1

Was the "Immobilizer System Check" performed?



Go to Step 2

Go to Immobilizer

System Check

2

Recheck the DTC on ICU.

1. Key position is “OFF”.

2. Install the scan tool on vehicle.

3. Key position is “ON”.

4. Check the DTC on scan tool.

Is DTC B0007 stored?



Go to Step 3

Refer to

Diagnostic Aids

3

Check the immobilizer communication line circuit.

1. Key position is “OFF”.

2. Disconnect the immobilizer control unit (ICU).

3. Disconnect the engine control module (ECM).

4. Check the immobilizer communication line circuit

for an open, short to ground, or short to voltage.

Also, check the ICU and ECM ignition feed circuits for
an open or short to ground and the ICU and ECM
ground circuit for an open.

Was a problem found?



Go to Step 4

Go to Step 5

4

Repair or replace the immobilizer communication line
circuit.

Was the action complete?



Verify repair



5

Recheck the DTC on ICU.

1. Key position is “OFF” and keep the position for

more than 30 seconds.

2. Key position is “ON”.

3. Check the DTC on scan tool.

Is DTC B0007 stored?



Go to Step 6

Verify repair

6

Recheck the DTC on ECM.

1. Key position is “OFF” and keep the position for

more than 30 seconds.

2. Key position is “ON”.

3. Check the DTC on scan tool.

Are below DTCs stored?

P1649 (C24SE)



Go to Step 7

Go to Step 9

7

Perform the immobilizer programming functions.

(Refer to "Important information on Programming")
• Engine control module (ECM).
Was the action complete?



Go to Step 8

Go to Step 11

8

Recheck the DTC on ECM.

1. Key position is “OFF” and keep the position for

more than 30 seconds.

2. Key position is “ON”.

3. Check the DTC on scan tool.

Are below DTCs stored?

P1649 (C24SE)



Go to Step 11

Go to Step 12