2001 Cummins N14 will not start, engine warning light on.

Not sure about Cummins, but Detroits won’t start at all.

 

Bypass coolant level with a paper clip. Most likely your problem. Just because its full, don't mean its reading it.

Or mechanically check oil psi.

 

Paper clip no longer needed. At least not on my 2000. Simply unplug the sensor. Yellow check engine light should come on, and stay on, but not the red light, and it won’t shut down. Jumping the plug with paper clip should turn yellow light off. Low coolant should show up on diagnostic blink code. Gotta be the fuel line or filter between tanks and pump sucking fuel. Mine had a bad coolant sensor before the overhaul that was intermittent. I thought it was the pigtail, as I’ve had this problem more than once, since getting the Truck 12 yrs ago. Also had a check valve on head go bad while it was in the Shop. To further complicate things, I had dosed it with killem and it finally started working. Had a problem after idling when taking off, of white smoke, and missing. I thought for sure it was sucking air. It would get real bad, change filters, and still do it a bit. I’ve since double dosed it with Killem, and the problem is gone. I think the slime was blocking a pick up tube in tank. Finally after a couple treatments, I see black slime floaties in the primary filter. Point being. I know how aggravating it can be, especially after spending all that money. Got to be something simple.

 

Welp seems like you have him taken care off. I'll be off.

 

When the cam timing sensor fails more often than not there are no codes.
The timing cam sensor is a common failure on a N14. Replace it and
maybe keep a spare and the socket to change it in the truck.

 

Lol, just trying to help. He needs someone with Cummins knowledge. That’s not Me. I’m not even a real Mechanic. Just a parts changer. I only gave my 2 cents because I saw no one replied yet after 4 hrs. Maybe someone else can help him. I can’t. Now that I think of it, maybe Cummins are different than Detroit’s. I assumed the Freightliner wiring was the same. Might need a paper clip for Cummins. I apologize if I sounded arrogant.I had a lot of time on my hands yesterday and today. Took Me 50 hrs to get unloaded.

 

Keep us posted.