2014 Freightliner Cascadia Cruise Control Sometimes Not Working?

Cruise control can be a number of things-
Everything from a bad wire coming from ECM- To a simple Clutch switch.
Ive seen bad Clocksprings also
TPS by the throttle pedal- Unplug it- and plug it back in-See if any difference

 

Does the Jake brake work when the cruise goes out ? My 14 was doing the same , the fix was cheap , under the dash by petal .

 

could be a clutch switch

could be a brake light switch (like on mine)

these i do believe can be found at the pedals under the dash.

 

check to see if the jakes aren't working when the cruise isn't. if so then its the clutch switch.

if the jakes work but cruise doesn't, check to make sure the micro switch on the brake pedal isn't depressed slightly telling the ECM you're applying the brakes.

short of that hook up the OEM engine diagnostic tooling and use that to tell you what is stopping the cruise enabling

 

Yeah if the Jake and cruise dont work clutch switch. It's a easy fix .

 

then its a brake switch or another parameter in the ECM stopping it enabling. OEM diagnostic software will be the fastest way to pin point what exactly