System Outline
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
Current is always applied from ECU-B fuse to terminal SYSB of the memory seat ECU, from PWR SEAT fuse to terminal +B of the memory seat ECU.
With the ignition switch turned on, current flows from ECU-IG fuse to terminal IG of the memory seat ECU and from the GAUGE2 fuse to terminal No. 3 of the A/T indicator light switch.