How to Program Keys to a Toyota or Lexus Vehicle When a "Traditional ReFlash Service" Has Been Performed on an ECU or Immobilizer Module

If you need to learn how to program keys to a reflashed ECU or Immobilizer then read on!

If a "Traditional ReFlash Service" has been performed on a Toyota or Lexus ECU or Immobilizer then you will need to program a key or keys to the vehicle. This article is specifically for reflash services performed by International Key Supply but could be similar if the services were performed elsewhere.

Typically when International Key Supply performs a programming service, the transponder (or key) that we send you along with the module is ready to start the vehicle. In certain cases, however, when either the data in a module is corrupt/damaged or the customer specifically asks us to only perform the reflash service then no working keys will be provided.

If you are reading this article then the service that we performed for you requires that you program a key or keys to the vehicle once you receive the module. We will have included in your package the number of unprogrammed transponders or keys that you requested with the Mail-In Module Service.

Here are the steps to program keys:

Step 1: Make sure that the vehicle's battery is fully-charged or hooked up to a jump pack.

Step 2: Reinstall the ECU or the Immobilizer in the vehicle.

Note 1: After you install the ECU or Immobilizer it will be in "Automatic Registration Mode" meaning the vehicle is ready to learn new keys.

Note 2: You will need to close the programming cycle after you are done programming the keys. You have two ways of closing the programming cycle:

1. Program three keys into the vehicle. This should automatically close out the programming cycle.

2. If you do not wish to program three keys into the vehicle then you will need to manually close out the programming cycle after programming at least one key (see step 7).

Note 3: The security light will blink until the first master key is inserted in the ignition.

Step 3: Insert the first master transponder key into the ignition lock cylinder for registration. The security light should remain "on". Do not turn the key. Wait about 15 seconds. Remove the key from the ignition. (Remember, if this is the only key you want to program, skip to step 7. If you wish to program more keys, continue to step 4).

Step 4: Insert the second master transponder key to be registered. The security light should remain "on". Do not turn the key. Wait about 15 seconds. Remove the key from the ignition.

Step 5: Insert the third transponder key to be registered. The security light should go out after a couple of seconds. Do not turn the key. Remove the key from the ignition.

Step 6: When you are done registering keys, remove any key that might
be in the ignition. The cycle is now closed. Verify that the security light has gone out.

Step 7: (ignore this step if the security light automatically went out after you programmed the third key) Manually closing the programming mode: If the security light is still illuminated, either because it did not automatically go out after you programmed the third key OR you chose to program less than three keys, pump the brake pedal 5 times, or cycle the ignition cylinder on to off and back on again 5 times to close the programming cycle.

Completing the Job: If the procedures above complete properly and the theft light operates as indicated, attempt to start the vehicle. If the vehicle cranks and starts your job is done.

However, if the vehicle cranks but does not start, the ECU or Immobilizer Module may need to be resynced. Follow the procedure below to perform the resync.

NOTE: Keep in mind that these Toyota and Lexus vehicles will always crank, even without a programmed key. Do not confuse a crank and no start with a no crank situation.

Steps to ReSync The ECU or Immobilizer:

Step 1: Insert an already learned master key into the ignition lock and turn to the ON position. Do not try to start the vehicle.

Step 2: Use a suitable jumper (to short) terminals 3 and 14 on the OBD2 port for 30 minutes. During this 30 minute window, you will see many, if not all of, the lights on the instrument cluster flash or illuminate. This is normal.

Step 3: The Engine Control Unit should now be resynchronized with the Immobilizer. Remove the key from the ignition, remove the short from the OBD2 connector, and then re-insert the key to start the vehicle.

NOTE: It is VERY important that the vehicle that you are trying to register/program keys to must have a properly working "key buzzer/dinger". If the key buzzer/dinger is not working in the vehicle that you are trying to register/program keys to, you will never be successful. If you have a key buzzer/dinger that is not working you will have to repair or resolve this issue before you can register/program keys to the vehicle.