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 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) [09/2016 - 12/2018]: Wiring Diagram