Welcome to the BBS. I'm sure that as an engineer, you can appreciate a thorough and complete description of the problem. If you notice your chosen subject, it leaves little to get the proper people to read your thread. Of the veichles represented here, one of the longest legacies of veichles, the latest and greatest are not paramount. That being said.
You can read the codes yourself from any chrystler computer by turning the key on and off three times in a row, then leaving the key in the on position. (don't go to the start position, just to on or run) The check engine light will start flashing in a code sequence. By using a factory technical service manual or other refrence you can decode this information in no time, revealing the problem so that you yourself can fix.
I'm sure somebody else on the board konws more about pulling codes, you can use a search function at the top of the post listing to do a complete search of past responses, I'd suggest "TJ diagnostic codes" then searching using AND, All posts, returning '999' posts (its a bug in the search, if you list 25 at a time, it only GIVES you 25).
'77 CJ-5: 304/T-150/D-20 F-D44 R-9" Power 4 wheel disk, 36X12.5 swampers