Fleet Truck?

The 1st is the Low coolant sensor at the bottom of the coolant reservoir, if it is low the engine will not start. The 2nd is low oil if you are 2 gallons low the same thing will happen.

Trust me, we checked everything and those two items are always on the top of my list as well as the fuse going to the ECM that is located in the battery box area (why its not in the fuse panel I'll never know).

It was just some wonky, who knows why code that even Freightliner couldn't figure it out. Clear it out and no problems. We haven't had a problem since.