94 Civic Lx ABS Light on (and groaning noise when it's not)

Hi,

I have a peculiar situation involving my ABS light. The situation is as
follows

1.) When I start the car there is a low groaning noise (maybe sort of
like a metallic brushing groan) that occurs only once.
2.) The ABS light comes on and remains on for he duration of the drive
3.) however, sometimes, the ABS light doees NOT come on and in these
cases, the groaning noise continues, occuring every 3 to 4 seconds! In
these cases, I can turn the car off and restart it until the ABS light
does not come on and the groaning will have gone away.

Has anyone had a similar experience or have any idea what might be
causing this?

I really appreciate all your help!
Ben....