The written report that I was given after my truck was in for the last time stated that the truck would not regen while using cruise control.
I have the same question, I only have 8K on my 6.7 and I couldn't tell you if it has ever went into Regen, except when I took it in for the last flash, the mechanic said they ran it through?How can I tell when it goes into the regen? I have put on 14000 miles in the last 3 months and havent noticed anything yet.
Observations from my truck on the AU flash - there shouldn't be any regen at idle however if you happen to be in a regen required state with a regen in progress when you come an idle state the EGR will remain closed (giving that fuel knock / rattle sound) and the latent heat in the DPF will make the exhaust hot enough to ignite stuff but there shouldn't be any fuel dosing occurring so the manifold EGTs will be 'normal' if you're at idle with sustained 1200+ manifold EGTs then something is wrong.
Regen is the process in which these trucks inject diesel into the exhaust causing enough heat to Burn out the soot buildup in the filters.What the heck is regen?