Isuzu KB P190. Service manual — part 1481

11A-26 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)

Data List

No.

No.

No.

No. Strings

Strings

Strings

Strings Note

Note

Note

Note

1

Ignition Status

On 12V /Off 0V

2 Transponder-Key

Transp.

Key

#

The number of the key currently

programmed

3 Transponder

Status

Correct/Incorrect TP-Key

4

Transponder-Key 1 Status

Programmed / Not Programmed

5

Transponder-Key 2 Status

Programmed / Not Programmed

6

Transponder-Key 3 Status

Programmed / Not Programmed

7

Transponder-Key 4 Status

Programmed / Not Programmed

8

Transponder-Key 5 Status

Programmed / Not Programmed

9

Immobilizer signal

Transmitted / Not Transmitted

10

Engine Request

Received / Not Received

11

Vehicle Speed Output

Veh.

Speed signal

12

Immobilizer Relay

Active 0V / Inactive 12V

13

Security Wait Time

Active / Inactive

IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-27

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 battery

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, Immobilizer

control unit (ICU), Engine control module (ECM).

NOTE: 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 by

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 transmitter
(key) on the vehicle.

11A-28 IMMOBILIZER SYSTEM (C24SE, 4JA1-T)

Diagnostic Trouble Code (DTC) list with ECM

•••• Immobilizer Control Unit (ICU)

DTC

Description Note

B0001 REPLACE ELECTRONIC CONTROL UNIT

(ECU) (IMMOBILIZER FAULT)

This error code appears if a RAM /ROM Error was

detected or the EEPROM is defect.

B0002 IMMOBILIZER NOT PROGRAMMED

Immobilizer control unit is not programmed.

B0003 TRANSPONDER KEY PROBLEM

･Reading of Transponder information failed with ignition

on transponder has a fault.

･Hardware fault in reading circuit.

B0004 IMMOBILIZER COIL CIRCUIT (ANTENNA

COIL FAULT)

Immobilizer coil has a fault.

B0005 COMMUNICATION LINE W VOLTAGE LOW

Short circuit to ground or open circuit.

B0006 COMMUNICATION LINE W VOLTAGE HIGH

Short circuit to 12V.

B0007 NO ENGINE REQUEST RECEIVED

No ECM Challenge.

B0008 WRONG TRANSPONDER KEY

Incorrect security code response received.

B0009 NO TRANSPONDER KEY PROGRAMMED

Transponder security code table empty

B0010 UNKNOWN TRANSPONDER KEY

Transponder security code not valid.

•••• Engine Control Module (ECM: Gasoline Engine {C24SE})

DTC

Description

Note

P1626

No Response From Immobilizer

Refer to Engine Control system section

P1631

Received Response Was Not Correct

Refer to Engine Control system section

P1648

Received Incorrect Security Code

Refer to Engine Control system section

P1649

Security Code & Security Key Not

Programmed

Refer to Engine Control system section

IMMOBILIZER SYSTEM (C24SE, 4JA1-T) 11A-29

Diagnostic Trouble Code (DTC) list with Engine Immobilizer Unit (4JA1-T Diesel Engine)

•••• Engine Immobilizer Unit

Code

(DTC)

Description Detecting

Condition

B0011 TRANSPONDER KEY PROBLEM

Transponder code unsuccessfully read 5 consecutive

time. (No completely read in 500ms transponder code)

B0012 WRONG TRANSPONDER KEY

Immobilizer program no executed.

B0013 IMMOBILIZER NOT PROGRAMMED

Processing program no executed.

B0014 NO TRANSPONDER KEY PROGRAMMED

Processing to save the transponder key in the control unit

not Executed.

B0015 FREQUENCY SIGNAL Lo

Lo level (less than 2.5) input during the Hi level was being

output to the communication line.

B0016 FREQUENCY SIGNAL Hi (Diesel)

Hi level (more than 2.5v) input during the Lo level was

being output to the communication line.

B0023 ANTENNA COIL OPEN

Antenna coil not connected.

B0024 WRONG TRANSPONDER RESPONSE

Transponder response signal with challenge is wrong.

B0055 EEPROM ERROR

Write and read cannot be correctly made to and from the

EEPROM in the control unit.