DTC C2121/21: No Signal from Transmitter ID1; DTC C2122/22: No Signal from Transmitter ID2; DTC C2123/23: No Signal from Transmitter ID3; DTC C2124/24: No Signal from Transmitter ID4; DTC C2125/25: No Signal from Transmitter ID5; DTC C2181/81: Transmitter ID1 not Received (Test Mode DTC); DTC C2182/82: Transmitter ID2 not Received (Test Mode DTC); DTC C2183/83: Transmitter ID3 not Received (Test Mode DTC); DTC C2184/84: Transmitter ID4 not Received (Test Mode DTC); DTC C2185/85: Transmitter ID5 not Received (Test Mode DTC) [08/2013 - ]: Wiring Diagram
WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.