ABS Activating Constantly After Hub Bearing Replacement – 1999 S70 Base

[S70Fan729]

1999 Volvo S70 Base, 170,000 miles, U.S. model.

About six months ago, I experienced occasional speedometer/odometer dropout, and ABS and brake lights on the dash. This was also accompanied by occasional ABS activation while braking. This sounded like a bad module, so I replaced the it with a refurbished one from Midwest ABS. That fixed everything except for rare activation when braking normally. My mechanic suggested cleaning a sensor if it got worse, but the issue went away on its own so I never bothered with it.

Recently I had the front right hub bearing replaced. After that, the ABS activates nearly every time I brake. It doesn't feel normal either, the brake pedal pulses much faster than if I was skidding in snow. I assumed the front right sensor was affected during the hub job, so I took it out and cleaned it. After reinstalling, the pulsing stopped, but ABS and check engine lights came on.

CEL codes: P0600 and P1054

ABS codes (from 850 OBD2 app): 0010, 0011, 0070, 0092, 0095. What's weird is the first two of these codes pointed to a missing/faulty signal from the left front sensor, when I never messed with that one. The other three correlate to a faulty pump motor signal and faulty control module communication.

A few days later, I tried cleaning the front right sensor again. The lights went away, but the constant ABS activation came back. My brakes are still effective, but the constant pulsing cannot be good for the system, and I have to brake a bit harder as a result.

From my research it seems like its either the sensor itself of the ABS ring. It was a bit difficult to get a good look at the ring and I don't have a picture of it, but it did look a bit rusty. Looking for advice on what the problematic part is here before I spend any money. Thanks!

[xanthefin]

Out of interest look at Exrapolation Counters at Live (ABS/BCM (CAN)) at the App does they show any funny business like going too high. Then too Velocity ones if any like that left one shows compared right or back one difference too much.

[abscate]

If the tone rings on the axle are rusty they will trigger abs sensor faults, so get the axles off and new tone rings on, about $5 each plus labour. You are in western Ny so they are all rusty