Circuit Description
WARNING: This page is about a different car, the 2004 Toyota RAV4. 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 passenger side J/B ECU through the RDA line. The RDA line is diagnosed by the passenger side J/B ECU, so check the DTC as well in case of the failure of the wireless function.