2007 ISUZU KB P190 DTC CHECK

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: W hen 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: W hen 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.
W as a problem found? 
Go to Step 5 Go to Step 6
5 Repair or replace the DLC (Data Link Connector)
circuit.
W as 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.
W as a problem found? 
Go to Step 7 Go to Step 8
7 Repair or replace the ICU ignition feed and ground
circuits.
W as 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.
W as 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

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ISUZU KB P190 2007

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.
W as 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)
W as 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")
W as 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")
W as the action complete? 
Go to Step 19 
19 Operate the DTCs by "Clear the Information" with
scan tool.
W as the action complete? 
Go to Step 20 
20 Attempt to start the engine.
Did the engine start? 
System OK Refer to
Diagnostic Aids


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ISUZU KB P190 2007

11A-34 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)
B0001 REPLACE ELECTRONIC CONTROL UNIT (ECU) (IMMOBILIZER FAULT)
Step Action Value(s) Yes No
1
W as 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 B0001 stored? 
Go to Step 3 Refer to
Diagnostic Aids
3 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.
W as a problem found? 
Go to Step 4 Go to Step 5
4 Repair or replace the immobilizer unit (ICU) circuit.
W as 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.
W as the action complete? 
Verify repair 


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ISUZU KB P190 2007

IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-35
B0002 IMMOBILIZER NOT PROGRAMMED
Step Action Value(s) Yes No
1 W as the "Immobilizer System Check" performed?
 Go to Step 2 Go to Immobilizer
System Check
2 Check the immobilizer programming functions.
• Immobilizer control unit (ICU).
If a problem is found, repair as necessary.
(Refer to "Important information on Programming")
W as the action complete? 
Go to Step 3 Go to Step 5
3 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 B0002 stored? 
Go to Step 4 Verify repair
4 Replace the immobilizer control unit (ICU).
IMPORTANT: The replacement ICU must be
programmed the security data by scan tool.
W as the action complete? 
Verify repair 
5 Check the immobilizer programming functions.
• Engine control module (ECM).
• Immobilizer control unit (ICU).
If a problem is found, repair as necessary.
(Refer to "Important information on Programming")
W as the action complete? 
Verify repair Go to Step 6
6 Replace the key and lock cylinder assembly and
immobilizer system (ICU and ECM).
IMPORTANT:
• ICU and ECM are not replacing simultaneously.
• After replace lock cylinders, perform the following
below the items.
• Program the immobilizer system.
(Refer to "Important information on Programming")
W as the action complete? 
Verify repair 

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ISUZU KB P190 2007

11A-36 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)
B0003 TRANSPONDER KEY PROBLEM
Step Action Value(s) Yes No
1
W as the "Immobilizer System Check" performed? 
Go to Step 2 Go to Immobilizer
System Check
2 Check the key.
Is a key peculiar to a vehicle? 
Go to Step 3 Refer to
Diagnostic Aids
3 Check the immobilizer programming functions.
• All transponder (Key).
If a problem is found, repair as necessary.
(Refer to "Important information on Programming")
W as the action complete? 
Go to Step 4 Go to Step 5
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 B0003 stored? 
Go to Step 5 Verify repair
5 Recheck the DTC.
1. Non-OEM parts switch is "OFF" or remove the Non- OEM parts.
2. Remove the accessory and another key from key.
3. Move the vehicle to a new location.
4. Key position is “OFF” and keep the position for more than 30 seconds.
5. Key position is “ON”.
6. Check the DTC on scan tool.
Is DTC B0003 stored? 
Go to Step 6 Verify repair
6 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.
W as a problem found? 
Go to Step 7 Go to Step 8
7 Repair or replace the immobilizer coil (antenna) circuit.
W as the action complete? 
Verify repair 
8 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 B0003 stored? 
Go to Step 9 Verify repair

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ISUZU KB P190 2007

IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-37
Step Action Value(s) Yes No
9 Replace the immobilizer control unit (ICU).
IMPORTANT: The replacement ICU must be
programmed the security data by scan tool.
W as the action complete? 
Go to Step 10 
10 Check the immobilizer programming functions.
• Immobilizer control unit (ICU).
• All transponder (Key).
If a problem is found, repair as necessary.
(Refer to "Important information on Programming")
W as the action complete? 
Go to Step 11 
11 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 B0003 stored? 
Go to Step 12 Verify repair
12 Replace the transponder (Key).
IMPORTANT: The replacement transponder (key) must
be programmed the security data by scan tool.
W as the action complete? 
Verify repair 


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ISUZU KB P190 2007

11A-38 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)
B0004 IMMOBILIZER COIL CIRCUIT (ANTENNA COIL FAULT)
Step Action Value(s) Yes No
1
W as 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.
W as a problem found? 
Go to Step 3 Go to Step 4
3 Repair or replace the immobilizer coil (antenna).
W as 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.
W as the action complete? 
Verify repair 


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ISUZU KB P190 2007

IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-39
B0005 COMMUNICATION LINE W VOLTAGE LOW
Step Action Value(s) Yes No
1
W as 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.
W as a problem found? 
Go to Step 4 Go to Step 5
4 Repair or replace the immobilizer communication W
line circuit.
W as 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.
W as the action complete? 
Verify repair 


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TO MODEL INDEX
ISUZU KB P190 2007