I have a 91 sedan Deville Cadillac that not wants to start due to no power on the injector coil
Does that mean that the engine control module is defective and has to be replaced

There is gas going to the injectors
There is power on the spark plug
The starter work
The wiring in between injector and ECM are good


Any help would be appreciated

that would be my guess, but its better to hook up a diagnostic tool and verify before you do anything, could be something as simple as a bent terminal on the injector, or a corroded connection any number of things. check every point along the harness, including inside the plugs, and make sure everything is as it should be, then hook up the diagnosic tool, and see where you are.

So there is not a device like a sensor that tell the EMC ok is time to fire a particular injector that could be defective


A by the way thanks for advice

Moving to appropriate forum, and welcome to AF hidroela.

If you don't have power on either injector wire when the ignition is on, I would look for a bad fuse, ignition switch going out, or a broken wire in between these parts and injectors. Most systems put constant voltage (with ignition switch on) on one wire, and turn the injectors on and off with the other wire running to the computer. It's easier on the computer to turn the ground side on and off, so most cars are that way.