Vauxhall Zafira 2001 1.6 - Fault Code - clewsy01

Hi, guys, my Zafira again started briefly mis-firing again today, but I am wondering if anybody can shed any light on this, FUELSYS1 - OL -Fault.

what could cause that and what does it mean?. When I cleared all the info and the misifre fault codes it has been fine.

cheers michael