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 signal from the transmitter will be input to the body ECU through the RDA line. The RDA line is diagnosed by the body ECU, so check the DTC in case of failure of the wireless function. For circuit diagram, see Fig 1.