The car should start just as it did with the test connector, with no IMA or other trouble indicator lights, and should work properly. MIMA cannot operate yet as the MIMA disable switch has not been plugged in.
If you cannot start, start and have a trouble code, and a reset will not fix it, turn off the car, and go to the ECM area first. carefully examine the wires and see if any of the rear T connections have pulled out, or the flying Male to Female junction. This is like an open wire to the computers, and the car will not work.
If the ECM wired are all plugged in properly, carefully redress the wires and tape the whole thing as a bundle to assure that the pins cannot pull out. I also would recommend taping each of the flying leads, but leaving the clear center so you can see if properly connected.

If no IMA or Check engine lights, and power supplies look good to this point, turn off the car, and connect the disable switch, making sure the switch is turned on.