EMD_DRIVER
Say what?!?!
its not that the ecms die.some of the early 94s dont have the obdII programing.
I don't know how relevant this is, but I had my old 94's ECM flashed to the latest version and it enabled the OBDII port on it. The OBDII worked great after that!
Some time after I sold the truck, the buyer called me and asked why he could get nothing from the EEC port under the hood. I guess having the OBDII port enabled, disables the EEC port.