Engine Immobilizer Systems: Other Lexus LS III

NEW TRANSPONDER KEY CODE

Note. This must be done when a new transponder key ECU is installed. The new transponder key ECU is in automatic key code registration mode. Up to 3 key codes and one sub-key can be registered at one time. In automatic registration mode, last key registered becomes sub-key.

1. Security indicator will flash until first key is inserted into ignition switch. Insert NEW key in ignition switch.
2. Once key registration is under way, security indicator should turn off. After key registration is complete, security indicator should illuminate. Remove NEW key.
3. If programming additional keys, repeat process starting with step 1 . If additional keys do not need programming, procedure is complete. Security indicator should go out once last key (sub-key) is registered.
4. After registration is complete and system is operating normally, when ignition key is removed from ignition lock cylinder, security indicator should flash indicating system is properly functioning. If a key is not inserted into ignition switch with transponder key ECU in automatic registration mode, security indicator will remain illuminated indicating keys have not been registered. If ignition key registration cannot be completed with transponder key ECU in automatic registration mode, a code 2-1 will be displayed by security indicator, and when inserting the already registered ignition key, a code 2-2 will be displayed by security indicator.

ADDITIONAL MASTER KEY

Note. Additional master key may be registered by 2 different methods: using ignition switch, or using LEXUS scan tool. It is possible to register up to 5 master key codes and 3 sub-key codes.

Using Ignition Switch

Note. Ensure driver's door is closed and key is not inserted in ignition switch.

1. Insert registered master key in ignition.
2. Perform this step within 35 seconds. Turn ignition switch on/off 5 times. Open/close driver's door 6 times. Remove master key from ignition.
3. Perform this step within 10 seconds. Insert new key to be registered in ignition.
4. After one minute, additional master key is registered. Security indicator should turn off. If programming additional keys, repeat process starting with step 2 . If additional keys do not need programming, remove master key from ignition.

REGISTRATION OR CHANGE OF KEY NUMBER

Note. Ensure this operation is performed when transponder key ECU is replaced. Key number is stamped on key number plate.

ERASURE OF TRANSPONDER KEY CODE

Note. There are 2 different methods to erase the transponder key code: using ignition switch, or using LEXUS scan tool. All other master and sub-key codes are deleted. When using ignition key which was used before deleting, it is necessary to register the code again.

Note. Ensure driver's door is closed and ignition key is not inserted in ignition switch.

1. Insert master key in ignition.
2. Perform this step within 35 seconds. Turn ignition switch on/off 6 times. Open/close driver's door 7 times. Security indicator will be off.
3. Perform this step within 10 seconds. Remove master key. Security indicator should flash for one second, then go off. Procedure is now completed. Key code should now be erased. If key cannot be removed from ignition, key code deletion is canceled. Security indicator will turn off. Repeat procedure from step 1 .

POWER SOURCE CIRCUIT

1. Check MPX-1 and IG2 fuses. Replace fuses as necessary. If fuses are okay, go to next step.
2. Turn ignition on. Measure voltage (backprobe) between transponder key ECU terminals No. 2 (Black wire) and No. 14 (White/Black wire). (Схема №3) About 10-14 volts should be present. Turn ignition off. Disconnect transponder key ECU connector. Measure voltage between transponder key ECU connector terminal No. 1 (Violet/Yellow wire) and No. 14 (White/Black wire). About 10-14 volts should be present. If voltages are not to specification, go to next step. If voltages are to specification, check next component listed in «TROUBLE SHOOTING SYMPTOMS»(ref-26717-S09401078922001010800000) table.
3. Check wiring and connectors between transponder key ECU and ground. Repair or replace wiring as necessary. If wiring is okay, check next component listed in «TROUBLE SHOOTING SYMPTOMS»(ref-26717-S09401078922001010800000) table.

PIN VOLTAGE TESTS

Turn ignition on. Measure voltage between specified terminals of transponder key ECU. (Схема №3) See TRANSPONDER KEY ECU TERMINAL VOLTAGE SPECIFICATIONS table. If voltage is not as specified, repair wiring harness or replace components as necessary. If voltages are as specified, replace transponder key ECU.

TRANSPONDER KEY ECU TERMINAL VOLTAGE SPECIFICATIONS