What does this mean: P0602 Checksum Error

I am having a few problems right now and trying to narrow it down and not sure what this code is.

 

Most if not all downloaders would throw that code a while back. I know the newer Smarty versions no longer throw that code.

If you are running an older Smarty version you should upgrade to a current one, clear Codes, load new program and then go back to stock. You should not throw the code any longer.

It is typically a stored code and does not affect engine performance.