V70 ABS problem
 

I have an intermittent ABS problem which is now getting worse. At first the ABS would pulse when turning left at low speeds with light brake application but it's now happening when turning in either direction. The STC activates and cuts power for no reason so I sometimes have to switch it off.

Strangely if I accelerate hard the ABS light will come on and I get the ABS message on the DIM. When the ABS light is on the car becomes jerky on the throttle and feels as though the engine is shunting about when changing gear.

Today when I started the car I could hear the ABS pump running immediately while still stationary and the speedo was flicking up and down between 0 and 5 mph.

I was hoping this would be a dud sensor or cracked tone ring but it seems like there may be more to it.

Any advice appreciated