Immobilizer Programming (Except PRIUS): Notes
WARNING: This page does not describe the selected car, but rather 17 other vehicles, including the 2003 Toyota Tundra, 2003 Toyota Tacoma, 2003 Toyota Sienna, 2003 Toyota Sequoia, and 2003 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
In the case of having lost all the already registered master ignition keys, you are not able to do additional registration or deletion of ignition key codes. You must change the Engine Control Module (ECM) and then perform ignition key registration.