The 2015 cascadia with dt12

If it has the California idle sticker, it won't idle for more than a limited time at a rpm higher than 800, if I remember right, idle speed is one of the parameters; we have some that have the sticker and others that don't, mine doesn't and will idle at pretty much any speed, and the book says 900. Be aware that there are mixed feelings at most manufacturers about idle, and many have discouraged idling since the 60s, maybe even before that.

It should be in the manual if it's a factory setting, but finding things in the manual is difficult for many.

I doubt the transmission matters as to whether the idle is easy to use or not.

 

We have no idle restriction other than following the myriad locality rules, and the company is leasing the trucks from an owner that won't buy or fix APUs, and has tried EPUs and won't do those, either.

It doesn't seem to bother the DD15 all that much, other than loading the DPF(not DEF) with a little soot that is regenned in about 10 minutes or less, either with a forced while parked or by driving off and doing a passive.

The forced regen is accomplished at 1100 rpm without the roar and race of the older Series 60 or Cummins ISX for upwards of half an hour.

If you want to drive for a company, you should try to do as they ask(demand) or move on to another. Stop asking for advice on how to beat the restriction and deal with it with the company. BTW, the new Schneider EVOs apparently can idle. At least the new one that parked next to me somewhere in IL (I think) could. It wasn't hot or cold out, either. We had several threads on this issue with Schneider trucks and the temp sensor locations near the exhaust.