2004 ISUZU TF SERIES warning

IMMOBILIZER SYSTEM 11A-3

General Description
The immobilizer system consists of the four major
components which are Engine Control Module (ECM),
Immobilizer Control Unit (lCU), transponder, and scan
tool (Tech-2).
This system can be activated by a correctly programmed
transponder and starter switch is set to OFF.
This system can be deactivated by a correctl
y
programmed transponder key connected with a correctly
programmed ECM and a correctly programmed lCU.
While the system is on :
The starter cut off relay deactivates function of starter,
and the fuel injector power source is deactivated also.


Check Engine lamp is flashing.


Warning buzzer is operating.
(With antitheft system)






Gasoline Engine (6VE1, C24SE)

LTW3BALF000101

IMMOBILIZER SYSTEM 11A-23

Menu
The following table shows which functions are used for
the available equipment versions.









 



 

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NOTE: Before going to programming process, Tech-2
indicates instruction as follows.

060R200289
DTC
On OBD has two options available in the Tech 2 DTC
mode to display the enhanced information available.


Read DTC Info Ordered By Priority


Read DTC Info As Stored By ECU
Clear DTC Information
To clear Diagnostic Trouble Codes (DTCs), use the
diagnostic scan tool "clear DTC information" function.
Tech-2 Data Display
Use the Tech 2 Data Values only after the On-Board
Diagnostic System Check has been completed, no
DTC(s) were noted, and you have determined that the
on-board diagnostics are functioning properly.
The Tech 2 data values represent values that would be
seen on a normally-immobilizer system.
Check Vehicle Identification Number (VIN)
1.
Select "Body" and "Immobilizer".
2.
Select "Additional Function" and "Read ECU
Identification".
3.
Shows up VIN on tech-2 display.
Reset Immobilizer (Reset Immobilizer
Control Unit)
1.
Select "Body" and "Immobilizer".
2.
Select "Additional Function" and "Reset
Immobilizer".
3.
Enter the security code and press Confirm.
4.
Reset Immobilizer screen shows up with warning.

See the following screen.

060R200279

11A-34 IMMOBILIZER SYSTEM

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

11A-36 IMMOBILIZER SYSTEM

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 11A-37

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

ANTITHEFT SYSTEM 11B – 3
Service Precaution
WARNING:
THIS VEHICLE HAS A SUPPLEMENTAL RESTRAINT SYSTEM (SRS). REFER TO THE SRS COMPONENT AND
WIRING LOCATION VIEW IN ORDER TO DETERMINE WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS WIRING. WHEN YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS WIRING, REFER TO THE SRS SERVICE INFORMATION.
FAILURE TO FOLLOW WARNINGS COULD RESULT IN POSSIBLE AIR BAG DEPLOYMENT, PERSONAL
INJURY, OR OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
CAUTION:
Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact
part number for that application. ISUZU will call out those fasteners that require a replacement after
removal. ISUZU will also call out the fasteners that require thread lockers or thread sealant. UNLESS
OTHERWISE SPECIFIED, do not use supplemental coatings (Paints, greases, or other corrosion inhibitors)
on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener
torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the
correct tightening sequence and specifications. Following these instructions can help you avoid damage
to parts and systems.
DTC20 Broken wire to door lock actuators ............................................................ 11B – 42
DTC21 Remote key 1 with random code out of capture range ............................ 11B – 43
DTC22 Remote key 2 with random code out of capture range ............................ 11B – 44
DTC23 Remote key 3 with random code out of capture range ............................ 11B – 45
DTC24 Remote key 4 with random code out of capture range ............................ 11B – 46
DTC25 Remote key 5 with random code out of capture range ............................ 11B – 47
DTC28 Input immobiliser short circuit to ground .................................................. 11B – 48
DTC29 Broken wire to immobiliser ......................................................................... 11B – 49
DTC31 Actuator driver door defect ......................................................................... 11B – 50
DTC32 Actuator passenger door defect .................................................................. 11B – 51
DTC36 Broken wire to driver door........................................................................... 11B – 52
DTC37 Broken wire to passenger door ................................................................... 11B – 53
DTC41 Driver door micro switch unlock defect ..................................................... 11B – 54
DTC42 Driver door micro switch lock defect .......................................................... 11B – 55
DTC43 Driver door micro switch dead lock defect ................................................ 11B – 56
DTC44 Passenger door micro switch lock defect................................................... 11B – 57
DTC45 Passenger door micro switch unlock defect .............................................. 11B – 58
DTC47 Battery voltage for door lock actuators is missing ................................... 11B – 59
DTC50 A/D converter defect or battery voltage less than 9 volt ......................... 11B – 60
DTC51 E E P ROM defect .......................................................................................... 11B – 61
DTC52 E E P ROM not programmed by ISUZU ...................................................... 11B – 62
DTC55 Control unit defect ........................................................................................ 11B – 63
DTC123 Output flasher short circuit to grpund or broken wire ........................... 11B – 64
DTC125 Output alarm horn broken wire ................................................................ 11B – 65

11B – 8 ANTITHEFT SYSTEM
ANTI-THEFT INDICATER SIDE TURN SIGNAL , HAZARD
WARNING LIGHT ; RH
ANTI-THEFT HORN FRT TURN SIGNAL , HAZARD
WARNING LIGHT ; RH
ENGINE HOOD SWANTI-THEFT
CONTROLLERRR DOOR SW ; RH
FRT DOOR LOCKACTUATOR ; RHFRT DOOR KEY SW ; RHFRT DOOR SW ; RH
RR DOOR LOCK ACTUATOR ; RHFRT DOOR SW ; LH
RR DOOR LOCK ACTUATOR ; LH RR DOOR SW ; LH
FRT DOOR LOCKACTUATOR ; LHFRT DOOR KEY SW ; LH
SIDE TURN SIGNAL , HAZARD
WARNING LIGHT ; LH FRT TURN SIGNAL , HAZARD
WARNING LIGHT ; LHRELAY ; HAZARD
RR TURN SIGNAL , HAZARD
WARNING LIGHT ; LH
RAW4C0XF000201
COMPONENT WIRING LOCATORS (LHD)

11B – 28 ANTITHEFT SYSTEM
Arm/Disarm Signal Test
Arm/Disarm signal test is used to check
abnormalities in arm/disarm signal circuit.
1. Select “Body” and “Antitheft”.
2. Select “Actuator Test” and “Arm/Disarm Signal
Test”.
3. Observe the data list.
4. Insert the key into door key cylinder.
5. Remove the key into door key cylinder.
Horn Signal Test
Horn signal test is used to check abnormalities in
horn signal circuit.
1. Select “Body” and “Antitheft”.
2. Select “Actuator Test” and “Horn Signal Test”.
3. Observe the alarm sound.
4. Push “active bottom”.
5. Check the alarm sound function.Turn Signal Test
Turn signal test is used to check abnormalities in
turn signal circuit.
1. Select “Body” and “Antitheft”.
2. Select “Actuator Test” and “Turn Signal Test”.
3. Observe the flasher lamp.
4. Push “active bottom”.
5. Check the flasher lamp function.
Theft LED Test
Theft LED test is used to check abnormalities in
theft LED signal circuit.
1. Select “Body” and “Antitheft”.
2. Select “Actuator Test” and “Turn Signal Test”.
3. Observe the antitheft LED.
4. Push “active bottom”.
5. Check the antitheft function.
Arm/Disarm Signal Test
Arm/Disarm Signal DisarmedElectronic System; Anti Theft Warning
Quit
ArmDisarmed
RAW4B0SH000201
Horn Signal Test
Horn Signal Inactive 12VElectronic System; Anti Theft Warning
Quit
ActiveInactive
RAW4B0SH000301
Turn Signal Test
Turn Signal Inactive 12VElectronic System; Anti Theft Warning
Quit
ActiveInactive
RAW4B0SH000401
Theft LED Test
Theft LED OffElectronic System; Anti Theft Warning
Quit
OnOff
RAW4B0SH000501