Truck Repair: Unknown ECM code, celect, flash code

Question
Hi! My Celect Plus M11 recently showed fault code 128s254 12 with red indicator "Stop ENG". What does it mean? Can I repaire it?

Thanx =)

Answer
Is that what the truck computor says?Try using the cruise control to get the 3 digit flash code.Turn cruise to ON,then hit either the SET or RESUME switch & count the CHECK ENG light flashes.There will be a short pause between digits & a STOP ENG light between codes.