Remote Up/Down Function does not Operate: Description
WARNING: This page is about a different car, the 2011 Lexus IS 350 and 2011 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.
When the engine switch is on (IG), the multiplex network master switch assembly sends remote up/down signals to each power window regulator motor assembly via the LIN communication line.