I just read on a diesel forum that the Dodge Ecodiesel 'sort of' has an engine brake but its much different from the 6.7. It works with the cruise control. When the cruise is on and you go down a hill, it will automatically shift down to prevent speeding up above the cruise setting. It's not a brake at all but just a computer setting.
It's a far cry from the exhaust brake on the 6.7. they said that if you mess with the exhaust on the ecodiesel trying to add a brake, you'll set off every engine code in the computer.
