Ford: My 97 Probe wont start, volt ohm meter, digital volt ohm meter

Question
Hi Ragu i have a 97 Probe Gt with the 2.5 24v V6 with 5 speed man. i have a problem where on occasion it will not fire when you try to start it cold. the motor spins over very easily but there is no spark. I have had a brand new distributor installed as i was told it is more than likely the modulator and while this appeared at first to fix the problem the next day it was the same. I then had some work done on the computer and this appeared to work for about 5 days it then failed to start for about 5 minutes and then started without any work being done simply trying again it then went for about 3 days without a fault and then this morning refused to start and has not wanted to start all day. The air temp here is very mild at the moment so this is not a factor.
I would very much appreciate any feedback to help solve this very frustrating problem
Kindest Regards Greg P New Zealand

Answer
Locate the two connectors that plug into the distributor, a 3-cavity connector and a 6-cavity connector. If the vehicle has injector pulse and no spark, test the trigger signal from the engine control (ECM) module to the ignition control module (ICM), which is located inside the distributor. The Yellow/Black trigger signal wire is located in the 6-cavity connector at the distributor. The trigger signal from the ECM should be tested using a labscope or digital storage oscilloscope (DSO). Back probe the trigger signal wire with the connectors plugged in and look for a 0-4 volt sawtooth pattern while cranking the engine. The signal can be a 0-3 volt square wave pattern on a failed ICM and will read approximately 1.5 volts on a digital volt ohm meter (DVOM) while cranking. The most important thing to remember is if there is any type of signal from the computer to the ICM and all the powers and grounds are good, the distributor has failed and will need to be replaced. Use a wiring diagram to verify all the powers and grounds at the distributor. NOTE: Wire colors may vary by model year and engine size.