geroj is definatly onto something there
with all these codes dealing with voltage issues all over the place i would certainly check the battery and load test it. If bad then replace and then see how truck runs. Most of these codes will dissapear probably but with those that are persistant , try clearing them, if any return then deal with those.

if you have never been into the computer system through the dash before i would not do it without 'onhand' assistance. Even with the manual not knowing what you're doing could result in bad things happening. Even as much as i or geroj or anyone else may want to help you with this part i wouldn't recommend it without 'onhand' assistance.
Just my.02 on this...
you can do what you want though

good luck