Wiring Diagrams
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.
For anti-theft wiring diagrams, see ANTI-THEFT for the 2002 model, and ANTI-THEFT for the 2003 model in SYSTEM WIRING DIAGRAMS in ELECTRICAL.