2016 Freightliner Detroit Automatic 12spd going to Nuetrual

You'll have to connect with DL8 and see if it is storing any faults. A lot of times, you wont get a check engine light, but will have multiple stored transmission codes for aborted shifts, etc.

 

Maybe the truck decided it didn’t want to drive during rush hour..
So if it starts at 430-630, park about 4-415, shower/and a nap may be in order

 

Here's some info on eCoast for the dt12 copied from Detroit service letter:
eCoast is a feature that can improve fuel economy (with or without cruise control). When conditions permit, the transmission shifts to Neutral and the engine goes to idle. When the conditions listed below terminate eCoast, the transmission will automatically select and shift into the proper gear. When eCoast is active, an "E" is displayed in the gear display window on the instrument cluster (Cascadia) or in the interactive dash display (New Cascadia). The eCoast function does not initiate when any of the following occur: · the accelerator pedal is pressed. · the service brake pedal is pressed. · the engine brake is in use. · the speed limiter is active and the maximum speed is exceeded. · PTO (if equipped) is in use. · eCoast is disabled if the DPF is in regeneration mode. - Steep downhill grades - Below 50 mph