I'm having problems starting my 2500hd GMC/duramax w/ allison when its warm and I turn it off for a few minutes it won't restart. The engine cranks but will not start. My dealer can't figure it out. A different dealer told me that it was from fuel thining out when turned off (15 min) and was losing pressure in the fuel system and then did not have enought pressure to start. My normal dealer says he sees a code for the NSBU and that is what the problem is. I have had no transmission issues. loss of gear indicator, and no codes in the message box.

Would the NSBU control the fuel flow to inhibit starting?

Beside they told me it was about $500.00 to replace which does'nt sound right to me.

I have searched under NSBU but have found no similar problems.


Thanks

Philip