I have a 2007 xc70 - 150K...

I routinely get the ABS warning light with an "Brake assist service required" as the associated message. This usually happens during or after a sharp right hand turn?.....

IDEAS????

 

I've had no experience with these matters but, posts on this subject are always followed by advice to fully inspect the notched ring and sensor wiring.
I believe a VIDA diagnostic will point to the effected wheel should it come to that.

 

VIDA will give codes - not sure if they get stored or if you need to scan when this is lit. Usual suspects are the pedal position sensor, the pressure sensor or a wheel speed sensor. Have you had any recent brake work? Sometimes that can alter the brake pedal position and a power bleed may help.

 

no brake work done.....