What is an ignition module? On vehicles with electronic ignition systems, points were replaced with an ignition control module and cam lobes were replaced with a trigger device. The trigger device, also referred to as a magnetic pick up or Hall effect sensor (located inside the ignition distributor) sends a signal to open and close the ground circuit to the ignition coil to fire the spark plugs. As it current flows thru the trigger unit, the module turns the current back on. It's an a very accurate method of controlling this procedure. Another advantage of the electronic ignition system is that it is able to produce higher voltages, up to twice the voltage than that of prior conventional ignition systems.
What are the symptoms of a defective ignition module? If a module is defective, the vehicle is usually completely dead. The engine won't run because there's no trigger voltage to the ignition coil.