Code 259 Cummins isx

ive been having boost issues won’t boost more than 25psi. Today the stop engine light came on. So I turned the key hit the dionostic switch. It flashes twice the five then nine and the repeats itself. So I’m guessing that’s a code 259 from what I read it the fuel shut off celinoid. It has been taking about 10 seconds to shut off once the key is off. Will this derate the engine? Can I drive it about 70 miles home to fix it? Or am I reading it all wrong? It’s a 99 570 600hp
Thanks

 

I’ll be putting it on in the am. Hopefully this stops the derate
Thanks

 

Is there a way to clear the code without a computer? I un hooked the battery cables for about a hr. It's still there. Or will it just become inactive and run ok if that was the problem? I've changed it but have not run it yet.