I would call Cummins, not Freightliner on this.
It could be a NoX sensor, could need regen,or several other things. I donít think starting it will do anything, if the after treatment device is working, it needs lots of heat, Run at highway speeds, not just starts or idle.
They have removed easy manual regen from RVs because of the dangers of ultra high exhaust temps in RV camping environments. It is also not usually necessary, given RV drive patterns. Dodge 3/4 ton trucks, with the same ISB engine donít have manual regen switch either.
Call CUMMINS to see what they advise. The advice usually given is to RUN at highways speeds and let it do a natural regeneration.
2018 Thor Palazzo 33.2
2009 Jeep Liberty