If your ecu get´s rpm, then you need to verify that the output wires are indeed sending a signal to the coil.
Best would be an oscilloscope.
But you could unhook the wire from the coil, and measure continuity to ground while cranking the engine, you should if you multimeter has a beep function hear the beep come on and of. Or connect a light bulp to 12v on the other side, it will then turn on and off