freightliner 2009 columbia, turn off while driving

What code is it showing? Sounds like it's de-rating due to a fault

 

Check your battery connections. The computer has it's own wire directly to the battery. It's a small wire. Make sure all the nuts are tight. If the computer wire isn't tight it can cause it to shutdown

 

Check your coolant level. Top the coolant off. This happened to me before. Had a small leak and the comment would drop. Add coolant and your good.

 

Black in filter? You have a fuel filter pluging causing lack of power. Could be algae or fuel line breaking down, look in tank with a bright light and see how it looks, algae can be treated with additive or you need new fuel lines. Carry a few extra filters and supplies to change them if you treat for algae, also drain water off the bottom of tanks, better yet if your low on fuel drain it all and start clean.

A simple fuel pressure gauge would tell you if it is a fuel supply problem

 

Dead on! I have had older fuel lines do that before.They collapse inside and deteriorate.
It will show as black crud in the fuel filters.