2003 LEXUS LS430 immobilizer

Fig. 3: Identifying Customer Problem Analysis Check Sheet
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
The key has 3 codes: the key code (immobilizer code), the smart code and wireless code. All of these code types
need to be registered. Refer to REGISTRATION
for the smart code (wireless code) registration procedures.
1.DESCRIPTION OF CODE REGISTRATION

a. When adding master keys and sub-keys (additional registration).
1. Register the key code (immobilizer code) in the steering lock ECU.
IMMOBILIZER CODE REGISTRATION TABLE
2. Register the key code (smart code) in the steering lock ECU.
SMART CODE REGISTRATION TABLE
b. When replacing the steering lock ECU (new registration).
1. Register the key code (immobilizer code) in the steering lock ECU.
IMMOBILIZER CODE REGISTRATION TABLE
2. Register the ECU COMMUNICATION ID between the ECM and the steering lock ECU.
ECU COMMUNICATION ID CODE REGISTRATION TABLE
c. When replacing the theft warning ECU.
1. Register the ECU COMMUNICATION ID between the ECM and the steering lock ECU.
THEFT WARNING ECU CODE REGISTRATION TABLE
d. When replacing the ECM.
1. Register the ECU COMMUNICATION ID between the ECM and the steering lock ECU.
REPLACING ECM CODE REGISTRATION TABLE
e. When replacing the steering lock ECU and theft warning ECU at the same time.
1. Register the key code (immobilizer code) in the steering lock ECU.
Target ECUSee
Steering lock ECUStep 3
Target ECUSee
Theft warning ECUSee REGISTRATION
Target ECUSee
Steering lock ECUStep 2
Target ECUSee
Steering lock ECUStep 5
ECMStep 6
Target ECUSee
Steering lock ECUStep 5
Target ECUSee
ECMStep 6

IMMOBILIZER CODE REGISTRATION TABLE
2. Register the key code (smart code) in the steering lock ECU.
SMART CODE REGISTRATION TABLE
3. Register the ECU COMMUNICATION ID between the ECM and the steering lock ECU.
ECU COMMUNICATION CODE REGISTRATION TABLE
f. Erasure of key code.
1. Erase the key codes.
ERASING KEY CODES REGISTRATION DESCRIPTION
2.KEY REGISTRATION IN AUTOMATIC REGISTRATION (NEW REGISTRATION)
a. When an ignition key is inserted into the ignition key cylinder, the key code (immobilizer code)
registration is automatic. In this mode, a maximum of 4 key codes for 3 master keys and 1 sub-key
can be registered. Any order of registration for the master keys and sub-key is fine because the
steering lock ECU can distinguish between different types of keys.
HINT:
When a new steering lock ECU is installed, key codes (immobilizer codes) must be
registered in the steering lock ECU.
New steering lock ECUs are automatically set to automatic key code registration mode.
Automatic Key Code Registration
(New Registration)
Target ECUSee
Steering lock ECUStep 3
Target ECUSee
Theft warning ECUSee REGISTRATION
Target ECUSee
Steering lock ECUStep 5
ECMStep 6
Target ECUSee
Steering lock ECUStep 4

Fig. 4: Automatic Key Code Registration Flowchart (New Registration)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
When no key is inserted into the ignition key cylinder in automatic key code registration
mode, the security indicator remains on.
When the immobilizer system is operating normally and the key is pulled out, the security
indicator blinks continuously.
If the key code registration has failed in automatic key code registration mode, code 2-1 will
be output from the security indicator. Trying to re-register an already registered key will
cause code 2-2 to be output when the key is inserted. If the number of registered key codes

HINT:
The automatic key code registration mode can be forced to end when at least 1 key code (immobilizer
code) for the master key has been registered.
3.REGISTRATION OF ADDITIONAL KEY (ADDITIONAL REGISTRATION)
a. Register an additional key using the hand-held tester.
HINT:
A maximum of 5 master key codes and 3 sub-key codes can be registered.
Registration mode will end if each step is not completed within the specified time.
When the ignition cylinder or the key cylinder set is replaced, remove the transmitter module
from the original master key. Then install this transmitter module to a new key and use the
new key as the master key. If necessary, use this master key to register other keys.
Additional Registration

Fig. 6: Automatic Key Code Registration Flowchart (Additional Registration)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
A brief outline of procedures for key code registration is shown on this page. For more
detailed information, please refer to the hand-held tester screen's instructions.
When the immobilizer system is operating normally and the key is pulled out, the security
indicator blinks continuously.
If the key code registration has failed in automatic key code registration mode, code 2-1 will
be output from the security indicator. Trying to re-register an already registered key will
cause code 2-2 to be output when the key is inserted. If the number of registered key codes
exceeds the limit, code 2-3 will be output from the security indicator. The output details are
shown in step 2 (new re
gistration).

4.ERASURE OF KEY CODE
a. Erase key codes using the hand-held tester.
HINT:
All key codes are erased except for the master key, which is used for erasing the key codes.
In order to use a key whose code has been erased, a new key code must be registered.
Registration will be cancelled if each step is not completed within the specified time.
Erasing Key Code
Fig. 7: Erasing Key Code Flowchart

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
HINT:
A brief outline of procedures for key code erasure is shown in this information. For more
detailed information, please refer to the hand-held tester screen's instructions.
When the immobilizer system is operating normally and the key is pulled out, the security
indicator blinks continuously.
5.ECU COMMUNICATION ID REGISTRATION

Fig. 23: Identifying Waveform 2
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
1.DESCRIPTION
a. The ECM controls the vehicle's immobilizer system functions. Immobilizer system data and the
Diagnostic Trouble Codes (DTCs) can be read through the vehicle's Data Link Connector 3
(DLC3). In some cases, a malfunction may be occurring in the immobilizer system even though the
security indicator lamp is not illuminated. When the system seems to be malfunctioning, use the
hand-held tester to check for malfunctions and perform repairs.
2.CHECK DLC3
HINT:
The vehicle uses the ISO 15765-4 communication protocol. The terminal arrangement of the DLC3
complies with SAE J1962 and matches the ISO 15765-4 format.