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.
Sean