Audi Repair: audi a6 1.8 ABS light Flashing, audi a6, light flashes

Question
my abs light flashes only wen i am driving after 80km/hr...for example i strt the car it starts everthing normal..then while driving wen i reach 80km or more the ABS light flashes...i plugged a scanner onto it and got speed singal sensor for Rear left and rear right...i took them out they were dirty i thought that y it wasnt working then i cleaned them still the same...can u please help me
thanks

Answer
hello
what faults did you have? ( I'm looking for foult #). Also check the rins on the both Axles, when you remove sensor, look inside , spin the hub and check if there is no crack on the ring , I have seen this problem when ABS ring cracks and brakes loose. on the higher speeds, the ring may come loose causing the sensor get wrong reading and than light comes ON..
good luck     Greg