Recently bought a 1996 mustang gt, it has a problem with idling (goes up and down like it's hunting) and it has a hard start without brake cleaner. MIL is on, PATS flashing. No communication at OBD2 Port. I have tried cleaning the Throttle Body, disconnecting IAC, cleaned MAF. I checked for resistance at my OBD2 Port pins 4, and 5 and I get no resistance to ground. I have checked for continuity from the PCM harness to the obd2 port and it seems fine. The PATS light flashes very fast, I checked the code and it's giving 6 flashes which I read was no communication from the PCM. The MIL flashes very fast and I think it may be a related problem, not sure. The car has a manual transmission, with an auto. transmission harness with an auto. pcm. I suspect the PCM is bad, however I do not have much experience doing this and wanted some advice. Huge thanks for your time :)

well, pcm is bad, or wiring to pcm, or you have a shorted sensor that feeds the pcm. Good luck finding the culprit, it can be a COW


Huge thanks Scotty, I guess I'll look at the diagram and start unpluging sensors.