auto logic fault P0691 fault help

My first post ....
I am trying to find out how if possible to fix this fault (hoping not new fan assembly) :doh:

My l322 V8 is showing an auto logic fault of p0691 which I am led to believe is fan 1 control circuit low . I am in need of advise as to how to fix this issue any ideas ...

thanks to any one who can help but go easy as last time I touched a car it was when I had a mk 1 escort..