2013 Prostar no idle hvac no power

I have a 2013 prostar+ with the battery APU unit. I recently had an update while at the dealership for the HVAC but after leaving my no idle heater and AC do not work. Checked fuses in bunk and dash and all seem ok. Also, and may be unrelated, my engine is derating again and not getting boost. I just had fuel rail and fuel pump replaced in the last month. Engine ran fine until now. No codes. Thoughts? Freezing my ### off at night because I hate idling engine with egr. Please help!

 

Ok. They are connected... the bigger issue has turned out to be the derate. In the last couple hours it has gone bad quickly. New symptoms with derate are fuel filter filled much higher than normal, engine fan acting sporadic and mpg all over the place. I seem to be burning fuel at a record pace as well. I have now averaged 3.5 mpg over the last 600 miles. Any ideas what would cause this?

 

Can this be cleared with a forced regen? Or do I need to have DPF filter cleaned?

 

No check engine light. It may be a combo of both of the above. I went to Houston this week and I don't normally go south. I'm sure I bought some fuel that was not winterized. Also had a regen earlier this week, but it shut off after only about 5 minutes. Didn't feel like it was completed when it ended. I'll look into both. Thanks for the advice.

 

Ok... so replaced fuel filters, did forced regen (although it was only showing 10%) still no change. No boost and Mpg still in mid 3's. Engine fan still sporadic. Noticed a shudder when warming up at high idle. Still no codes. So thinking maybe a bad injector? Bad fuel pressure regulator? Air pressure sensor? Hate to keep throwing money at this thing as its been a money pit already. Oil is good but getting dark, no metal or diesel in oil. No excessive burning and at 12k since last change. Doing a PM next week since most filters are new at this point. Please send your thoughts (or maybe prayers). Thanks again.