Remote Keyless Entry System: Notes
WARNING: This page is about a different car, the 2002 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
In this system, the wireless door lock ECU receives weak radio waves transmitted from the transmitter built-into the ignition key, and outputs a signal to the instrument ECU (body ECU). Accordingly, all the doors can be locked and unlocked by remote control.