From your post I would assume he is driving the truck so I would certainly hit an auto parts store that reads codes for free, and take a pencil and paper to write down ALL the codes.
Nothing worse than "I think code was 1234, but not sure", lol
After you have all the codes written down have them reset(reboot) the computer to clear all the codes, the trans may start working again, but it would only be temporary.
Codes can be general or specific, so exact code number is important.
If they can't read the codes then computer is the problem and will need to be replaced
Last edited by RonD; 08-31-2014 at 04:34 PM.