I've got a 2000 Excursion with a P1280 ICP circuit low code that is stumping me. It started with a hard start/long crank and led into a running rough/no power. Inspected ICP sensor and connector and found damaged sensor and oil contamination in wiring pigtail. Replaced both with a Napa brand sensor and connector. Cleared codes and retested. Found code is still there. Plumbed in gauge to oil reservoir and checked low side oil pressure while cranking, found 50 psi. Plumbed in gauge to fuel filter housing and found base fuel pressure to be 60 psi while cranking. Found a ICP troubleshooting pinpoint test. Tested VREF and signals too ICP connector and found within spec. Disconnected PCM and ohm checked engine harness to PCM and found no issues. Monitored PIDS using FORSCAN. During cranking ICP is at 600 PSI, IPR is at 32%. After cranking for 65 seconds Engine finally started. ICP at 693 psi, IPR is at 28%, engine at 800 RPMS, total run time 1.5 minutes. If I shut the engine off and immediately try to restart it just cranks for probably 2 minutes and then starts but runs rough and tries to die. Im suspecting there is a short in the PCM itself but I would like to verify that for sure before I replace it. Any thoughts or suggestions?