I had the ABS light on the odd time on my old Civic and after a while it became constant. I tried looking for a fault code using the service connector but it was showing nothing, no faulty sensors etc. I really did not want to take it to a Honda main stealer as the price of a new sensor was £160 each and then there was the extortionate labour charges. I searched around on the internet and found that a good way to check for sensor errors is to measure each sensor for resistance using a multi-meter. I bought a cheapo multimeter for a tenner and checked each sensor by unplugging the sensor cable block and putting the meter probes into each sensor contact. One of the rear sensors was showing zero ohms so I knew that was the faulty one, the others were around 800 front and 600 rear. You can search on the net to find out what the resistance should be for each sensor. The front ones were higher on the Civic than the rear. I got a used sensor off Ebay for £25 and it fixed it. I guess it's maybe different with a Ford, but the stupid price of Honda parts made me research it and fix it myself, pleased I did must of saved me best part of £200. Just a thought.