If the light doesn't go out after driving for a while or a few days it may just be that the ABS sensor has to be pushed back in. It's usually the front ones. It follows the front brake lines to the top of the swivel pin and is covered in a ribbed plastic sheath. Clean the area real good and just carefully tap the sensor down. It can be done without removing the tire but it's a little harder to reach. I would try that first. Those sensors are pretty expensive if you have to replace them.
welcome to hell, I have been looking as this problem for months.
push them back in do not take then out
try all fuses and i mean all fuses
try all and any connection you can find
replace brake switch.
I have done all the above and mine is still not working, I am now looking to replace the wheel sensors.
mine works for around two weeks after i have pushed the sensors back in, I have replaced the sensor bushes.
if you sort it or get any good ideas let me know.