Circuit Description
WARNING: This page is about a different car, the 2003 Lexus IS 300 and 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
The door lock control switch circuit can be checked using DTC check. See DTC B1211/11: POWER WINDOW MASTER SWITCH ECU COMMUNICATION STOP under DIAGNOSTIC TESTS under MULTIPLEX COMMUNICATION SYSTEM article under COMMUNICATION DEVICES in ACCESSORIES & EQUIPMENT. For circuit diagram, see Fig 1.