ECU ISUZU TF SERIES 2004 Workshop Manual

IMMOBILIZER SYSTEM 11A-55

B0015 FREQUENCY SIGNAL LOW (Only 4JA1-T Engine)
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 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.
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-56 IMMOBILIZER SYSTEM

B0016 FREQUENCY SIGNAL HIGH (Only 4JA1-L Engine)
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 B0016 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 (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.
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 11A-57

B0023 IMMOBILIZER COIL CIRCUIT (ANTENNA COIL FAULT)
(Only 4JA1-T Engine)
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 B0023 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 

11A-58 IMMOBILIZER SYSTEM

B0024 WRONG TRANSPONDER KEY (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.

Transponder (Key).
W as a problem found?

Go to Step 4
Go to Step 5
4 Perform the immobilizer programming functions.
 Transponder (Key).
(Refer to "Important information on Programming")
W as the action complete?

Go to Step 5

5 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 B0024 stored?

Go to Step 6
Verify repair
6 Replace the transponder (Key).
IMPORTANT
: The replacement transponder (key)
must be programmed the security data by scan tool.
Was the action complete?

Go to Step 7

7 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 B0024 stored?

Go to Step 8
Verify repair
8 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

IMMOBILIZER SYSTEM 11A-59

B0055 EEPROM ERROR
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 B0055 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.
Was a problem found? 
Go to Step 4
Go to Step 5
4 Repair or replace the immobilizer unit (ICU) 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 

11B – 2 ANTITHEFT SYSTEM
Pin-outs ......................................................................................................................11B – 21
Pin- Assignment ........................................................................................................ 11B – 22
lmportant information on Programming .................................................................... 11B – 23
Security code ............................................................................................................. 11B – 23
Entering a code ......................................................................................................... 11B – 23
Tech-2 Scan Tool............................................................................................................ 11B – 24
Tech-2 Features ......................................................................................................... 11B – 25
Getting Started ......................................................................................................... 11B – 25
Operating Procedure................................................................................................. 11B – 26
Menu ..........................................................................................................................11B – 27
DTC ............................................................................................................................. 11B – 27
Clear DTC Information .............................................................................................. 11B – 27
Tech-2 Data Display................................................................................................... 11B – 27
Actuator Test ............................................................................................................. 11B – 27
Unlock / Lock Test..................................................................................................... 11B – 27
Arm / Disarm Signal Test ......................................................................................... 11B – 28
Horn Signal Test ........................................................................................................ 11B – 28
Turn Signal Test......................................................................................................... 11B – 28
Theft LED Test ........................................................................................................... 11B – 28
Programming............................................................................................................. 11B – 29
Erase remote keys..................................................................................................... 11B – 29
Program Remote Keys .............................................................................................. 11B – 30
ProgramAntitheft Waring......................................................................................... 11B – 31
Program Country Code ............................................................................................. 11B – 32
Program Vehicle Options.............................................................................................. 11B – 33
Tech-2 Data List ......................................................................................................... 11B – 34
DIAGNOSIS .................................................................................................................... 11B – 35
Diagnostic procedure................................................................................................ 11B – 35
Clearing Diagnostic Trouble Codes ......................................................................... 11B – 35
Verifying Vehicle Repair............................................................................................ 11B – 35
Diagnostic Aids ......................................................................................................... 11B – 35
Check the condition for system parts ..................................................................... 11B – 35
Check the Electro-Magnetic Interference (EMI) ..................................................... 11B – 35
Check the other items .............................................................................................. 11B – 35
Check the operation.................................................................................................. 11B – 35
Diagnostic Trouble Code (DTC) list.......................................................................... 11B – 36
Antitheft System Check ........................................................................................... 11B – 37
No Antitheft Lamp .................................................................................................... 11B – 38
DTC13 Security code not yet programmed ............................................................ 11B – 39
DTC14 No remote key programmed ....................................................................... 11B – 40
DTC16 Door lock actuators short circuit to ground ............................................... 11B – 41

ANTITHEFT SYSTEM 11B – 29
Programming
Programming antitheft function is used to input
security code for the antitheft system by tech 2.
If the remote key or ECU replaced, program as
necessary.
Erase Remote Keys
1. Select “Body” and “Antitheft”.
2. Select “Programming”.
3. Select “Erase Remote Keys”.
4. The following screen shows up.4. Confirm the following screen shows up.
Programming
F0; Erase Remote Keys
F1; Program Remote Key
F2; Program Anti Theft Warning
F3; Program Country Code
F4; Program Vehicle Option
RAW4B0SH000601
Not
OkayOkay Security Code
0000
Press ENTER Key to continue
060R200284
ConfirmSee Checking Procedure Before
Programming!
060R200289

11B – 30 ANTITHEFT SYSTEM
Program Remote Keys
1. Select “Body” and “Antitheft”.
2. Select “Programming”.
3. Select “Program Remote Keys”.
4. The following screen shows up.4. Confirm the following screen shows up.
5. Input the security code.
Programming
F0; Erase Remote Keys
F1; Program Remote Key
F2; Program Anti Theft Warning
F3; Program Country Code
F4; Program Vehicle Option
RAW4B0SH000601
Not
OkayOkay Security Code
0000
Press ENTER Key to continue
060R200284
ConfirmSee Checking Procedure Before
Programming!
060R200289

ANTITHEFT SYSTEM 11B – 31
Program Antitheft Warning
1. Select “Body” and “Antitheft”.
2. Select “Programming”.
3. Select “Program Antitheft Warning”.
4. The following screen shows up.4. Confirm the following screen shows up.
5. Input the security code.
Programming
F0; Erase Remote Keys
F1; Program Remote Key
F2; Program Anti Theft Warning
F3; Program Country Code
F4; Program Vehicle Option
RAW4B0SH000601
Not
OkayOkay Security Code
0000
Press ENTER Key to continue
060R200284
ConfirmSee Checking Procedure Before
Programming!
060R200289

ANTITHEFT SYSTEM 11B – 33
Program Vehicle Options
1. Select “Body” and “Antitheft”.
2. Select “Programming”.
3. Select “Program Vehicle Options ”.
4. The following screen shows up.4. Confirm the following screen shows up.
5. Input the vehicle options.
Programming
F0; Erase Remote Keys
F1; Program Remote Key
F2; Program Anti Theft Warning
F3; Program Country Code
F4; Program Vehicle Option
RAW4B0SH000601
Not
OkayOkay Security Code
0000
Press ENTER Key to continue
060R200284
ConfirmSee Checking Procedure Before
Programming!
060R200289