DTC C2121: No Signal from Transmitter ID1; DTC C2122: No Signal from Transmitter ID2; DTC C2123: No Signal from Transmitter ID3; DTC C2124: No Signal from Transmitter ID4; DTC C2181: Transmitter ID1 not Received (Test Mode DTC); DTC C2182: Transmitter ID2 not Received (Test Mode DTC); DTC C2183: Transmitter ID3 not Received (Test Mode DTC); DTC C2184: Transmitter ID4 not Received (Test Mode DTC) [06/2016 - ]: Wiring Diagram