Check engine light

They would have to do a scan on your check engine light to see what's wrong which I've never seen them ever scan one I would say no to being shut down

 

Not a dot thing
Air pollution Nazi might say something, highly unlikely you'll even come across them.
The engine may be on it's way to shutting itself down if you ignore it long enough...

 

I would be looking for a place to camp, that light is a warning telling the driver that something is not right, it can be something as simple as low coolant or it can be a warning coming from that def control crap which give it time may derate you, be planning on finding the problem somewhere not in the middle of the busiest city.

 

The check engine (or the MIL - Malfunction Indicator Light) is there to inform the driver of an active issue. I had a Maxxforce prostar that would throw a MIL light if it got a sensor misread, and it would stay on until either it got a certain number of "good reads" or is cleared by a tech with a computer/scanner. Most of the modern engines are similar. DOT is only looking for issues that are safety or log related for the most part (or major fluid leaks), not computer issues

 

I don't think a check engine light is part of the OOS criteria. This is a common thing with all vehicles. Something is wrong under the hood. It could also just be a bad sensor. Get it looked at ASAP.

 

Out-of-Service Criteria - CVSA - Commercial Vehicle Safety Alliance

 

I have been DOT’d a lot. Most enforcement guys don’t even know what type of truck you are driving, let alone the motor under the hood or any internal issues. The dash lights you worry about him seeing are the abs light for the truck and trailer, high beam indicator, signals, and low air warning. Engine wise they are listening for air leaks and looking for major fluid leaks, little else.

 

On Volvo, the check engine light could mean you're motor is about to become a grenade, or Volvo has a software update available.