On some modern cars, the ECM controls everything from timing to the fuel pump. Many others are not as reliant on it though. It depends on what type of car you have but if it's 2007 or newer, I doubt it would even turn over. If it's older and there's an issue with the ECM, you might notice it not to running as smoothly.
Bad ECM or ECM relay.
Yes
The ECM seldom goes bad, it can but it rarely does. A faulty crank sensor could give you those same symptoms. Check all other possibilities before you condem the ECM.
Number of possibilities.. bad batteries, bad starter, faulty connector the starter, bad ECM, faulty connection to the ECM. Can't narrow it down without knowing more details.
Bad ecm
Blown fuse, bad connection, or ground.
The ECM is supposed to ground the injector to make it work. Either the ECM is bad or something that tells the ecm to fire the injector is bad. TAke it to a mechanic.
Radiator fan could be bad, fan relay bad, fuse blown. Also if your ECT (engine coolant temperature) sensor is bad the ECM (computer) won't know to tell the fan to turn on.
There could be any number of problems causing a no start condition. No fuel, no spark, bad timing, clogged fuel filter, bad fuel pump, ECM bad, ECM fuse bad, Ignition fuse bad.... Too many to list.
The best way to tell on chrysler products you will have a data loss to your instrument panel and it will say no bus and most of your warning indicators on dash will be on, No data to diagnostic equipment or communication and of course stalling and a no start condition. Keenan Laws owner of Advanced Automotive tech Automotive ecm rebiulders 419-601-4369
Plug in a code reader. If you get no response, bad ECM or a bad wire/fuse going to or from it. But you may get symptoms of stalling,lack of power,bad fuel milage, and many more things that just don't seem right. But the code scanner will be you best angle of attack.
You