Is it alright to turn the engine off when truck is doing a passive regeneration?

Sure it dose. While some tucks prior to DEF also do regen's DEF is only used when doing a regen on any truck that has DEF.

 

Def is not the reason to do a regen yes it is used but not e reason to do one. The dpf is full and needs to burn off

 

The early DPF (non DEF) systems were the worst.

 

Cruise will only bump my idle up about 80rpm so I don't bother. However my truck idles every night and I never have issue. In fact it runs pretty much from the time I leave Sunday until I get home Friday except for fueling and the occasional shipper/receiver who wants it off. It might initiate 2 true regens a week, this is on a 2016 ISX Cummins. They also do full DPF services on our trucks every 150k which I think is extremely important for the proper operation of these systems. Most companies wait until they start giving trouble to do any maintenance and by then it's too late.