Here are a couple of threads that may help solve your ABS light issues. The key is taking a look at your reluctor rings through the speed sensor hole. I am not sure if it is noted in the other threads but the best way to get the new rings on is apparently to heat them up in the oven so they expand and slide right over the axle.

https://www.volvoxc.com/forums/showt...reluctor+rings

https://www.volvoxc.com/forums/showt...reluctor+rings

Necessary tools

https://www.volvoxc.com/forums/showt...114#post219114