ENG 0 is not a fault code itself. It is a diagnostic mode indicator displayed on the instrument cluster (typically on Freightliner Cascadia, Century, or Columbia). When the display shows ENG 0 , the system is waiting for you to enter a two-digit diagnostic code (01 through 99) to view active or stored engine faults.
If your Freightliner runs fine but shows ENG 0, it may be a historic code. Still check – it could be early warning for sensors or emissions system. Post the exact numbers in a truck repair forum (e.g., Rawze.com, TruckersReport) or consult Detroit Diesel Diagnostic Manual (DDEC VI or later). eng 0 code freightliner