2007 ISUZU KB P190 Circuit

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

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

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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ISUZU KB P190 2007

11A-40 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)
B0006 COMMUNICATION LINE W VOLTAGE HIGH
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 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.
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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ISUZU KB P190 2007

IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-41
B0007 NO ENGINE REQUEST RECEIVED
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 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.
W as a problem found? 
Go to Step 4 Go to Step 5
4 Repair or replace the immobilizer communication line
circuit.
W as 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).
W as 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

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ISUZU KB P190 2007

11A-46 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)
B0011 TRANSPONDER KEY PROBLEM (Only 4JA1-T Engine)
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 B0011 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 B0011 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 B0011 stored? 
Go to Step 9 Verify repair

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ISUZU KB P190 2007

IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-51
B0015 FREQUENCY SIGNAL LOW (Only 4JA1-T Engine)
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 B0015 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 immobilizer unit.
4. Check the immobilizer communication W line circuit for an open, short to ground, or short to
voltage.
Also, check the ICU and Engine immobilizer unit ignition feed circuits for an open or short to ground
and the ICU and Engine immobilizer unit 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 


BACK TO CHAPTER INDEX
TO MODEL INDEX
ISUZU KB P190 2007