I have a 2006 XE Frontier. A few weeks ago a hose busted and drained all the coolant from the truck, it ran hot, it died. My husband was a mechanic for 20 years and can usually fix anything. The head gasket was blown, so they rebuilt the motor completely. It will turn over, but won't start. It's got compression, fuel, but it's not getting a spark/no fire. Replaced cam and crank sensor, checked all coil packs, spark plugs and they are good. We even checked the sensors and wiring harnesses to make sure they were good after the replacments. Still Nothing. No codes are showing up. We found a PCM/ECU whatever from a local salvage yard. Same make, model, year, motor size, both with cruise control, both automatic. Still won't crank. Local Nissan dealer said for $125 they can tell me if the PCM is bad, but they won't fix it or program it since it's used. Would the PCM I got require programming if it's for an identical truck? Any other ideas of what can be wrong?