Originally Posted by xxtegra
what would cause this ? cut wires in the harness?
Yeah something shorting out to chassis somewhere probably.
I did see a link somewhere of a possible short somewhere near the alternator but cannot find the link now...the short could be anywhere and you need to trace it before frying another PCM.
It is possible you have a bad coil pack for instance which blows that part of the circuit....now you swap that bad coil pack with one in a different position and the bad coil pack blows another section of the PCM and so on.
It can be difficult to physically trace wires fraying to ground as the harness tends to take a long round about route...you will need to remove the battery, disconnect the PCM, measure all leads coming out of the PCM for continuity to ground using a good Multmeter.
You can get the circuit diagrams for your 2002 KJ here.....included in the 2002 KJ Service Manual.
There is no circuit diagram for the PCM itself but if you physically trace the blown components in the PCM to nearby PCM connector pins you can check where those connector pins go to in the circuit diagram Connector Pin-out Table....should narrow down your path to take ie. coil pack, injector etc.
Note that as stated before in your link, the coil packs all get +12 volts on one side while the other sides are grounded in turn by the PCM so if one of those leads goes to ground intermittantly the coil pack could burn out which in turn could cause that circuit to draw too much power and burn out the relevant Transistor/SCR in the PCM.