When repairing ford EEC-V PCM for various faults, start by probing each black SMD resistor on the backside. Those are of notoriously bad quality and they normally go open.
Please note you must have very sharp probes of high quality before attempting to measure each resistor. I recommend Probe Master 8000 series kit:
https://probemaster.com/8000-series-test-lead-master-kits
Prepare to replace 5-10 of them on each board.
Bigmac's tips och trix 