Rear brakes & ABS light

[apupi]

I just replaced the rear brake pads and rotors, after installing them, the ABS light came on.... Can someone help me explaining what I did wrong?
I read something about the ABS ring... is that the slotted circle inside the older rotors?
My A4 B5 is FWD.....

 

[johnie72]

Yep! you need to remove the old slotted ring and drive it onto your new discs. Be sure you haven't damaged the ABS sensor if you've driven it without the slotted ring.

 

[shineydave]

you won't damage the ABS sensor if the ring is missing, in fact the sensor is probably safer with the ring missing as there's no big lump of toothed steel spinning at high speed in close proximity to it. obviously the ABS won't work but it'd be safer, lol