Front Power Seat does not Operate with Front Power Seat Switch: Description
WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.
When a signal is input into the front power seat switch (seat ECU), the ECU manages the signals received from the front power seat switch LH and RH, and operates each motor When 2 or more signals are input, the motors only operate when the signals are from the slide switch and reclining switch.