The Renix has a serial output and does not store codes. It's read in real time with engine running. I think the dealers had a specific reader, and Snap-on made a module for some of theirs. I believe they're pretty rare, and as far as I know there's no handy consumer version as there is for many other systems.What would I be looking for to read "engine codes" from the diagnostic ports under the hood? In other words what did dealers and repair shops use? (I have an 89 4.0 XJ.) :dunno:
I know quite a long time ago 5-90 was trying to find the specs for the serial output to see if he could hack a serial computer connection, but it seems never to have materialized. I suppose somewhere someone on this earth must know what this thing puts out, and suspect that if one knew the specs it might not be that hard for a programmer to write a routine that reads the data on computer with serial input, but I'm not aware of anyone having actually done it.