I think you are absolutely correct in that the engine control computer is shutting off fuel at what most of us call the lpg lock-off, that Nissan engineers refer to as the 'interceptor valve', in the books, due to the ECU not seeing an important input from something in the vehicle's can bus.
While I would never suggest anyone tamper with any parts that are specified as "tamper proof" or "tamper resistant",,,
I think if someone were to open up the ecu wire plug connectors on the wire side they may well find a broken wire, and/or replace the wire harness, depending on the age of the truck. A newer truck still under the government mandated extended warranty for items related to the emissions controls may get a new harness at the factories expense so the factory engineers can look at the failure and try to figure out how to avoid it in the future, where a 10 year old truck may get the soldering pencil and a drip of super glue taken to the spot the wire pulled off the connector plug.
The legality of doing repairs to an item specified by government mandate to be 'tamper proof' and that the factory says requires replacement rather than repair is not something I would be wanting to be on the wrong end of telling someone to do, for someone else to profit from. and I do not know what Komatsu suggests as the proper way to repair a wire that has pulled loose from the pin.
I do know that in the past the factory has suggested a dab of Dielectric (spark plug boot) grease in each of the plugs during reassembly as a way to reduce moisture and related corrosion in those pins and sockets on the ECU.