Since my car has been acting up here latley I've done a ton of research on how the ignition system works(opti icm coil ect...) I came across this video that ges details on how a opti aka abits works and how
to diagnose it.
It kinda bugs me in a way when ppl assume right off the bat when their car is acting up they blame the opti. Now ,this way with the aod of the video they can follow this simple steps
Check to see if you have a signal from the PCM to the ICM on the white wire. While someone cranks it over, check the white wire to ground for 1-4 volts on the AC scale. If that's there, the problem is between the ICM and the coil.
2 of the wires go from the ICM to the coil. With key ON engine OFF, those 2 wires have 12 volts on them. Find them and be sure they have 12 volts with the key on. One of the other 2 wires left goes to ground. Find it and confirm it goes to ground. The last wire left is the one that carries the control signal. It will test out as I said on the AC scale when someone cranks it with 1 to 4 volts AC. Also measure the resistance of the wires on the opti harness.
If you are getting 1-4 VAC on the white wire it means your opti is sending pulses to the PCM which is sending signals to the ICM to fire. Then your problem is not the PCM or harness. It would be ahead of that which leaves the ICM, coil, and opti.
(Diagram courtesy of Shoebox)
Disconnect the ICM connector. Leave the coil connected. Turn key ON engine OFF. Check for dc voltage at harness terminal "A" to ground and and also "D" to ground. You should get 10v dc or more on both terminals.
If you get no voltage then its the coil or ignition fuse.
If you have good voltage, switch the meter to AC and connect the leads to terminal "B" and ground. Watch the metre while someone cranks the engine. You should see between 1 and 4 VAC. If you don't see the proper ac voltage the problem could be the optispark, the harness to the optispark, the PCM or any of the wiring in between.
Measure the resistance of your coil. If its around 5000 ohms or so its fine. Any higher than 7000 ohms means you should replace it. Measure the resistance of the opti harness and if it seems very high, replace it.
So then if your car passes all the above tests, its the opti.
The following information was found in camaroz28.
Buick Know How: LT1 Optispark (ABITS) Distributor Operation and Diagnostics - YouTube