This machine has the spectrum diagnostic system on it, you'll need the spectrum diagnostic software and the correct diagnostic cable and a laptop to diagnose any issues with this unit in realtime.
You can make the system utilize the MIL light and force it to flash the stored DTC's by locating the diagnostic connector and jumping terminals A and D, turn on the key and it will tell the ecm to move to diagnostic mode and force the dtc to be flashed by the MIL light.

there is a 4 pin diagnostic connector in the harness near the ECM, most likely located underneath the floor plate area.
I am not aware of any way to connect a handset to the ecm on these units.