13 — paper jam or paper path
On LaserJet models the 13 family covers jams and paper path sensors, and the digits after the dot narrow down where. Switch the printer off and work through the paper path in order: the tray, the inside, then the rear door. Pull sheets slowly in the direction the paper was already travelling and never backwards, since a torn fragment left behind causes the next three jams. If the code returns with the path visibly clear, a sensor or roller is the likely cause and that's a service job.
Related codes: 13