Isuzu KB P190. Manual — part 1482

11A-30 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)

IMMOBILIZER SYSTEM CHECK

Step Action Value(s)

Yes

No

1

1. Key position is "ON," engine "OFF."

2. Observe the check engine lamp.

Note: When a key switch is turned ON, check engine
lamp will turn on and a check engine lamp will be
turned off after a few seconds.

Is the check engine lamp "ON"?



Go to Step 2

Go to "No

Immobilizer

warning lamp"

2

1. Key position is "ON," engine "OFF."

2. Observe the check engine lamp.

Note: When a key switch is turned ON, check engine
lamp will turn on and a check engine lamp will be
turned off after a few seconds.

Is the check engine lamp "OFF"?

(Check engine lamp does not flash)



Go to Step 3

Go to

"Immobilizer

warning lamp on

steady"

3

1. Key position is "OFF."

2. Install a scan tool.

3. Key position is "ON."

4. Attempt to display immobilizer data with the scan

tool.

Does the scan tool display immobilizer data?



Go to Step 9

Go to Step 4

4

1. Key position is "OFF," disconnect the immobilizer

control unit (ICU).

2. Check the DLC (Data Link Connector) circuit for

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

Also, check the DLC ignition feed circuit for an

open or short to ground and the DLC ground

circuit for an open.

Was a problem found?



Go to Step 5

Go to Step 6

5

Repair or replace the DLC (Data Link Connector)
circuit.

Was the action complete?



Go to Step 3



6

1. Check the ICU 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.

2. If a problem is found, repair as necessary.

Was a problem found?



Go to Step 7

Go to Step 8

7

Repair or replace the ICU ignition feed and ground
circuits.

Was the action complete?



Go to Step 3



8

Replace the immobilizer control unit (ICU).

IMPORTANT:

The replacement ICU must be

programmed the immobilizer data by the scan tool.

Was the action complete?



Go to Step 3



9

Select "Display DTCs" with the scan tool.

Are any DTCs stored?



Go to Step 10

Go to Step 13

IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-31

Step Action Value(s)

Yes

No

10

Review and record for scan tool Failure Records data
and DTCs.

Was the action complete?



Go to Step 11



11

Following the DTC is stored.

Are there DTC B0001 or B0055 stored?

Go to applicable

DTC table after

Go to Step 12

Go to Step 12

12

Clear the DTCs by "Clear the Information "with scan
tool.

Did the DTCs Cleared?



Go to Step 12



13

Select "Display DTCs" with the scan tool.

Are any DTCs stored?



Go to applicable

DTC table

Go to Step 14

14

1. Key position is "ON," engine "OFF."

2. Observe the check engine lamp.

Note: If a key switch is turned ON, check engine lamp
will turn on and a check engine lamp will be turned off
after a few seconds.

Is the check engine lamp "flash"?



Go to Step 15

Go to Step 20

15

Check the engine control system.

If a problem is found, repair as necessary.

(Refer to section 6E: system check and DTCs)

IMPORTANT: The replacement ECM must be

programmed the immobilizer data by scan tool.

(Except 4JA1-L Engine)

Was the action complete?



Go to Step 16



16

Check the key.

Is a key peculiar to a vehicle?



Go to Step 18

Go to Step 17

17

Change into a peculiar key.

IMPORTANT: If replace the key, after replace lock
cylinders, perform the following below the items.
• Replace the keys and key cylinders.
• Program the immobilizer system.
(Refer to "Important information on Programming")

Was the action complete?



Go to Step 18



18

Check the immobilizer programming functions.
• Immobilizer control unit (ICU).
• Engine control module (ECM).
• Transponder (Key).
If a problem is found, repair as necessary.

(Refer to "Important information on Programming")

Was the action complete?



Go to Step 19



19

Operate the DTCs by "Clear the Information" with
scan tool.

Was the action complete?



Go to Step 20



20

Attempt to start the engine.

Did the engine start?



System OK

Refer to

Diagnostic Aids

11A-32 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)

NO IMMOBILIZER WARNING LAMP

Step Action Value(s)

Yes

No

1

Check the meter fuse for the instrument cluster
ignition feed circuit.

Is the fuse normal?



Go to Step 3

Go to Step 2

2

Replace the fuse.

Is the action complete?



Verify repair

Go to Step 3



3

1. Key position is "OFF".

2. Disconnect the meter.

3. Disconnect the engine control module (ECM).

4. Check the circuit between meter and ECM for an

open, short to round, or short to voltage.

Also, check the meter circuit for an open or short to
ground and the DLC ground circuit for an open.

Was a problem found?



Go to Step 4

Go to Step 5

4

Repair or replace the meter circuit.

Was the action complete?



Go to Step 5



5

1. Key position is "ON," engine "OFF."

2. Observe the check engine lamp.

Is the check engine lamp "ON"?



Go to Step 6

Go to Step 7

6

Repair or replace the meter.

Was the action complete?



Go to Step 7



7

1. Key position is "OFF".

2. Check the check engine lamp bulb.

Is the check engine lamp bulb normal?



Go to Step 9

Go to Step 8

8

Replace the check engine lamp bulb.

Is the action complete?



Verify repair

Go to Step 9



9

1. Key position is "OFF".

2. Connect the meter.

3. Connect the engine control module (ECM).

4. Key position is "ON".

5. Observe the check engine lamp.
Note: If a key switch is turned ON, check engine lamp
will turn on and a check engine lamp will be turned off
after a few seconds.

Is the check engine lamp "ON"?



Verify repair

Go to Step 10

10

Replace the engine control module (ECM).

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

Was the action complete?



Verify repair



IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-33

CHECK IMMOBILIZER WARNING LAMP ON STEADY

Step Action Value(s)

Yes

No

1

1. Key position is "OFF".

2. Disconnect the immobilizer control unit (ICU).

3. Disconnect the engine control module (ECM).

4. Key position is "ON," engine "OFF."

5. Observe the check engine lamp.

Is the check engine lamp "ON"?



Go to Step 2

Go to Step 5

2

1. Key position is "OFF".

2. Disconnect the meter.

3. Key position is "ON," engine "OFF."

4. Observe the check engine lamp.

Is the check engine lamp "ON"?



Go to Step 3

Go to Step 4

3

Repair or replace the meter.

Was the action complete?



Verify repair

Go to Step 5



4

Repair or replace the meter circuit.

(Between meter and ICU/ECM)

Was the action complete?



Verify repair

Go to Step 5



5

Check the immobilizer control unit (ICU) circuit.

1. Ignition "OFF," disconnect the ICU.

2. Check the ICU 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 6

Go to Step 7

6

Repair or replace the immobilizer unit (ICU) circuit.

Was the action complete?



Verify repair

Go to Step 7



7

1. Key position is "OFF".

2. Connect the meter.

3. Connect the immobilizer control unit (ICU).

4. Connect the engine control module (ECM).

5. Key position is "ON".

6. Observe the check engine lamp.

Is the check engine lamp "ON"?



Verify repair

Refer to

Diagnostic Aids