MGM Programing Questions

I have mgm 160/18 controller and I am not getting any beeps etc when trying to program the transmitter for throttle brake limits I wait 10sec nothing to let me know its in programming mode, it works fine using my pc, but arent you supposed to set transmitter limits first before anything? It does work I had adjust some throttle trim cause it was slowly creaping forward..also it has a dead spot in throttle before it moves forward, is this from transmitter limits not being set? Oh and I am doing all this with motor 1515/1y "disconnected" for safety ...do I have to have motor connected when doing this? Can I use just pc to set throttle brake limits? using a DX3.0 as transmitter...help ...thanks