Yes both the controller(s) and the TIU(s) have version 5.0. Is there any other way to verify that other than when you turn on the controller? I mentioned I will update them to 6.0. What is so baffling is that everything works except for the ability of the operator to perform the normal transformer functions (Whistle, Bell, and Direction) from the remote in one of the power districts. The track voltage responds in both districts to the controller input (verified with meter), and the engine will respond to the MTV, TSV and TZV soft key input. In the other power district (which uses the other TIU variable channel) everything works. If you reverse the input and output wires the power districts respond accordingly with only one having complete traditional engine control. Also, DCS works fine through all TIU Fixed and Variable Channels . Thanks for your help.