need help on P0507 code 1997 chevy cavalier 2.2

Ok, here is my problem. Car is throwing a p0507 code, I have changed the IAC, PCV and checked for vacuum leaks and it is still throwing the code. I have brought the car down to a shop to do a continuious test and they found that it throws the code only when the fan turns on. Not under and other load only the fan. They suggest to replace the computer as it may have a glitch. I have never heard of this. Please help as this is my sons car and it needs to pass inspection for him to go to school