What is the possible cause of a anti-lock failure warning in your Jaguar XJ6 I've run it for a while and it doesn't go away. Solutions anyone.?

I have been informed that a failure of any one of the wheel speed sensors will cause this trouble message to occur. These are located on the upper inboard side of the brake disc hubs,( four of them}. There are black wire leads coming from them with snap together round electrical connectors about 12 inchs long that tie into the body harness. Check your connections? Also, although I am not positive about this part but someone should know - you can test the wheel speed sensors with an ohm meter. I believe there should ne no continuity between ground and either pin inside the connector and continuity should occur between the two pins in the connector, but the ohm meter has to be set on a high scale.