Checked everything but we did diagnostic check and got and engine code P3008

I am sure you have gone through just about everything by now. Not sure of your experience or knowledge on engines. Are you looking for something specific or any general idea. Any one electrical connection that was missed can cause a no start. Does the fuel shut down solenoid open when trying to start? Have you verified all fuses are good? I have seen where someone will get in a rush and pinch the wire between the engine and trans. Since it is a diesel, have you bleed all the air out of the fuel system? Make sure all fuel lines are tight so it does not draw any air in. Some engines will not start unless they are turning over at 150 rpm. Does your starter drag, battery getting weak? I do not work on this model, but have over 40 years as a tech.