I am the owner of a 2000 S80 2.9 that is reporting OBD Code P1633. I also see the WarningMessages for "Brake Service Required" and "STC Service Required" displayed. The ABS and STC warning lights also come on then off. I also notice the trip odometer displays"dashes" for a short time, then displays the correcttrip mileage again.

Could this be a bad ABS Control Module or a problem withone of the speed sensors.

The car has new brakes and up-to-date Warranty Service.

Thanks!!!

 

I say bad ABS module.(Very common signs of it being bad)