Can anyone tell me what the potential causes for the engine light to illuminate on the dash are please?

Ours has been coming on & off for a while, but only when on the more severe corrugations. It started after I had changed the main fuel filter. I've checked the wiring connection which seems ok, but am wondering if somehow it could be the float mechanism at the bottom of the filter jumping around........ or something completely different. I recall it happened for a while when we were back home, but can't recall what resolved it, I think it may have just stopped by itself.