I have already searched and read through pretty much everything I could find on the immobilizer issue but none quite matches my exact issue or I would appreciate it if someone could help pinpoint the issue based on my symptoms.

My 2000 Acura TL was working perfectly fine, I parked it during the holidays and when I went to start it, the battery was dead, so I tried to jump start it, when I hooked up the jumpers, the car's alarm went off as normal, I used the key to unlock the car in the driver's side door and turned the alarm off. Unfortunately the battery was far too dead, so I just took it out and went to exchange it for a new one. When I plugged up the new one, I didn't hear any alarm so I thought that was strange, but everything seemed to work, but when I put the key in, the green key light just keeps blinking and of course it just cranks but won't start.

Anyone have any ideas?

 

The imobilizer is not recognizing the key.

Try removing the key from the key ring and try starting the car with just the one key.

Try a different key.

Reset the pcm by removing the clock fuse for 10 seconds.

 

I only have 1 key, there is nothing on that key ring except the key and the key fob, I tried removing the key and using only that, didn't work. I took out the passenger side fuse 13 7.5amp clock fuse for 30 sec then put back in, no luck either :\

 

I have the same issue every now and then. Dont know why it happens but mashing the brake pedal a few times (violently) usually make the light go solid and starts right up.