Now you see why I was asking you the series of questions pertaining to the battery , the series of events that you described was pointing to your battery. Don't throw away the original CPS because there was probably nothing wrong with it. You can use it as a backup, if you still have the other CPS installed I would go ahead and clean the battery terminals install the new battery hook it up make sure you tighten the battery terminals so that you cannot move the terminals on the post, then put your key in the ignition turn it to on / run position but don't start it, that way the security system will resync itself, give it a full minute or two then try and start the car, if the car starts and runs you've hit a home run and you're good to go if it starts but shuts off turn the key all the way to the left and then turn it back to the run position and let it resync itself again and then try and start it again. Good luck hope it works for you.