Attempted to cycle pump a few more times and noticed 4 letters in my trip meter. the letters were "Pdon". Have no idea what this is. any clue?

 

this happens when you cycle your ignition 3 times it flashes any stored codes you PCM has stored. PDON means it is done displaying codes.

 

thank you for the information. Where can I find out what other codes represent?

 

You can find them codes right here on this site. Here is the link. I printed it out and carry in in the truck notebook.
Good luckhttps://www.dieseltruckresource.com/faq/faq.php?display=faq&nr=115&catnr=25&prog=1&lang=en &onlynewfaq=1

Davey