^^^ I think Rob "nailed it". ^^^

I will bet MONEY this is not a component failure, it is a wiring problem due to rodent damage. For SOME reason, we see a lot of this (comparatively speaking) from those who store their cars or leave them sitting for a long time. The insulation on the wires must taste good.

I have read at least two threads here where someone has stored their car in a carport or barn and ended up with chewed wiring under the hood. If you are lucky, re-insulating the wires will do it - but I bet the PTCM has been damaged.