OK, before you commit to buying a new PCM, be sure the chassis grounds are good. I am not looking at a Manual right now (at work) but there are three pins on the PCM connector for power ground. Figure that out and see if they are 5 Ohms or less back to the chassis. One connection is right above the driver side headlight, another is in the vicinity of the ballast resistor for the blower on the passenger side firewall. Incidentally, the OBD1 connector is found dangling from the wire harness in this same neighborhood. The fact you recorded at least one code for the EGR indicates the PCM is at least somewhat functional. If you have a scanner, can you communicate with the PCM and clear the code? This would further indicate the state of health of the PCM. You may want to go ahead and replace the EGR soon. When the EGR fails, its often the vacuum transducer diaphragm that quits, allowing hot exhaust gas to leak into the vacuum system which can cause other mysterious problems. Also make sure the engine ground strap is sound and free of corrosion. The various grounds are common sources of gremlins and if you plop a 2-300 dollar "remanufactured" PCM down in that mess you'll still have all the same problems. The PCM can't furnish power ground if it doesn't have a sound connection to work with. You can also swap the fan clutch relay with the ASD relay(never mind this suggestion, I see you've covered that). Check from the return side of the ASD coil to pin 51 (or whatever for your year) of the PCM connector. Finally, I presume you've already eliminated the "Splice", right?
Last edited by vhinze; 10-25-2013 at 05:49 PM.