Automatic ecu in standard

I did an auto to manual swap on my car and the standard ecu didnt allow the car to start. So i swapped the ecu back to the automatic and it started right up. I didnt try to drive the car i just started it and turned it back off to see if it would start. My question is if i tried to drive my now standard car with the automatic ecu what would happen? Would it harm my car? Would anything blow up? Would it even drive? I just want to drive it out if the garage right now and to the lawn to wash it since the snow is finally gone and im going to get the chip reflashed in a couple of weeks but i just want to drive it a little bit.