When i use craig motes program i noticed that the check sum on the lower right of the screen is changing constantly. Is this supposed to do this or does it mean my ZIF socket and/or chip is loose?

 

That's the checksum of the data stream. It changes with the data.

 

Thanks,
one more question:

Could a loose zif socket and/or chip send a car into limp home mode. I am fairly sure that it could but am not sure. When in limp home mode do the fans come on at all times (similar to when checking error codes/grounding pin B)?