switch ISUZU TF SERIES 2004 Workshop Manual

IMMOBILIZER SYSTEM 11A-31

Diagnostic procedure


Once the cause of DTC is repaired or gone,
engine can be operated normally, and present
DTC becomes history code.


History code is canceled by no repeat failure on 25
consequence ignition key on afterward.


History code cannot be canceled by batter
y
connector disconnected.
Clearing Diagnostic Trouble Codes
IMPORTANT:
Do not clear DTCs unless directed to do
so by the service information provided for each
diagnostic procedure. When DTCs are cleared, the
Failure Record data which may help diagnose an
intermittent fault will also be erased from memory.
Verifying Vehicle Repair
Verification of vehicle repair will be more
comprehensive for vehicles with immobilizer system
diagnostic. Following a repair, the technician should
perform the following steps:
1.
Review and record the Fail Records for the DTC
which has been diagnosed.
2.
Clear DTC(s).
3.
Operate the vehicle within conditions noted in the
Fail Records.
4.
Monitor the DTC status information for the DTC
which has been diagnosed until the diagnostic test
associated with that DTC runs.
Following these steps are very important in verifying
repairs on immobilizer systems. Failure to follow these
steps could result in unnecessary repairs.
Diagnostic Aids
Check the condition for system parts.



Installation condition, poor connection, damage,
system parts malfunction. Harness, Fuse, Relay,
Immobilizer coil (antenna), Key, Meter, Immobilize
r
control unit (ICU), Engine control module (ECM).
NOE: Breakage of immobilizer fuse does not operate
immobilizer system. Check engine lamp flashes at this
time.

Check the Electro-Magnetic Interference (EMI)



Location of vehicle check

Move the vehicle to a new location and perform
the check again.


Non-OEM Parts.

Switch is "OFF" or remove the Non-OEM parts and
perform the check again.


Other

Remove the accessory and another key from key.

Check the other items.



Battery voltage is low.


Immobilizer programming functions.

Must be programmed immobilizer system.


Registration for security code, immobilizer control
unit parts number.


Key switch operation.

Immobilizer system may detect a history DTC b
y
the timing of ON-OFF of a key switch.


Active the immobilizer system.


Keyless entry system is malfunction.


Anti theft system is malfunction.

Check the operation

Check the operation "Lock / unlock" by using transmitte
r
(key) on the vehicle.

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

IMMOBILIZER SYSTEM 11A-35

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-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 

11A-40 IMMOBILIZER SYSTEM

B0003 TRANSPONDER KEY PROBLEM
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 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")
Was 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.
Was a problem found? 
Go to Step 7
Go to Step 8
7 Repair or replace the immobilizer coil (antenna) circuit.
Was 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

11A-50 IMMOBILIZER SYSTEM

B0011 TRANSPONDER KEY PROBLEM (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 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")
Was 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.
Was a problem found? 
Go to Step 7
Go to Step 8
7 Repair or replace the immobilizer coil (antenna) circuit.
Was 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

ANTITHEFT SYSTEM 11B – 1
SECTION 11B
ANTITHEFT SYSTEM
CONTENTS
PAGE
Service Precaution ........................................................................................................ 11B – 3
General Description ...................................................................................................... 11B – 4
Activating the anti-theft system.............................................................................. 11B – 4
Antitheft system alarm operating conditions ........................................................ 11B – 4
Function of a keyless entry system ......................................................................... 11B – 4
Status LED ................................................................................................................. 11B – 4
Hazard relay ............................................................................................................... 11B – 4
Switches .................................................................................................................... 11B – 4
Receiver......................................................................................................................11B – 5
Range of communication ......................................................................................... 11B – 5
Diagnosis ................................................................................................................... 11B – 5
Transmitter (into remote key) .................................................................................. 11B – 5
Transmitter (into remote key) power ...................................................................... 11B – 5
Super lock .................................................................................................................. 11B – 5
No proper transmitter is available, what should be done for the system ?........ 11B – 6
DIAGRAMS AND SCHEMATICS ................................................................................... 11B – 7
SYSTEM WIRING DIAGRAMS .................................................................................. 11B – 7
COMPONENT WIRING LOCATORS (LHD) ............................................................... 11B – 8
WIRING DIAGRAM (LHD).......................................................................................... 11B – 9
WIRING DIAGRAM (LHD).......................................................................................... 11B – 10
WIRING DIAGRAM (LHD).......................................................................................... 11B – 11
WIRING DIAGRAM (LHD).......................................................................................... 11B – 12
WIRING DIAGRAM (RHD with keyless) ................................................................... 11B – 13
WIRING DIAGRAM (Super Lock).............................................................................. 11B – 14
WIRING DIAGRAM (Super Lock).............................................................................. 11B – 15
WIRING DIAGRAM (RHD) ......................................................................................... 11B – 16
WIRING DIAGRAM (RHD) ......................................................................................... 11B – 17
WIRING DIAGRAM (Super Lock).............................................................................. 11B – 18
WIRING DIAGRAM (Super Lock).............................................................................. 11B – 19
WIRING DIAGRAM (Super Lock).............................................................................. 11B – 20
Antitheft control unit (A) .......................................................................................... 11B – 21

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

ANTITHEFT SYSTEM 11B – 7
DIAGRAMS AND SCHEMATICS
SYSTEM WIRING DIAGRAMS
M
M
M
M
M
M
M
M
- +
ANTITHEFT CONTROL UNIT BATTERY
(12V)
80A10A
ACC Ignition switch20A
10A
10A
antitheft horn
power supply
power supply
door lock motors
hazard relay(RH)
flashers(RH)
hazard relay(LH)
flashers(LH)
status LED
immobilizer controller
daiagnostc conector
groundlock lock
locklock lock alarm trigger
super lock
unlock unlock
(unlock)
(unlock)
unlock
driver door rear door(LH) rear door(RH)rear door(LH) rear door(RH)
assist door driver door assist doordriver door
assist door
driver door assist door
engine hood contact switch
door contact switch
auto door lock switch auto door lock
door lock cylinder
disarmwith super
lock without
super lock

11B – 10 ANTITHEFT SYSTEM
RTW48AXF025301
B
C
Horn
switch
B-71IG1&IG2
H-27 B-55
B-56
B-62
B-63
C-108
H-6B-65
Antenna
cable
B-52H-13
H-25
B-58
B-80(RH)
B-81(LH)
H-26
H-10
H-24
B-44B-43
B-73
H-7
RTW48AXF025301
WIRING DIAGRAM (LHD)