Have you not used it for a while? After I did not use mine(2001 P38) for appr. 3 mos., it quit working and I think I had the same code. Sorry I am no mechanic, but my cousin took apart the unit in the back and it was a small rocker arm that was stuck, needed to be wiggled and oiled. It was a small black rocker arm--sorry I can't be more specific, but if you can dismantle the unit and if you can't fix it, re-post and I will ask my cousin to ID what he oiled. All perfect now. I think basically if you can take the unit apart and move and wiggle everything and use the right oil. Sorry for poor help, but I hope this helps you in the right direction.