LED brake bulbs set ABS out of operation ??

a colleague of mine bought the ebay 2 brake light bulbs with several LEDs. now he has installed them and at once the ABS lamp lights up a short time later and is out of operation (brake test). now he thought it is probably on his car or something and gave them to me today. I also exchanged them for the normal pears and see there, also with me after a short time the ABS out… why is that??