Take your PCM to an Auto-Value store and have them reflash it for $69.00. If it is shot, they can tell you. Otherwise you have a wiring issue you need to resolve.

 

I had a very similar issue that turned out to be the pigtail connector for the coolant temp sensor. I used a scanner to read all sensor data, and the coolant sensor was reporting -40'F. I unplugged the pigtail and used a very small screwdriver to close the gap in the individual connectors inside th epigtail; basically, I made the connections tighter. After plugging back in, the temp sensor reads correctly and problem solved.

Just something to consider,
Thomas.