Finding faulty ABS sensor

[mnkiboy]

I have a 2003 Volvo V70 with a failing ABS / Wheel speed sensor. The traction control keeps cutting in even when driving gently. All wheel's and tyres are identical and the car was performing fine up until about a week ago. Tyre pressures have been checked and double checked, so i'm sure it's a sensor.

Question is how do I determine which of the 4 sensors is at fault? The issue originally only occurred when going round tight right hand bends eg roundabouts. It's now getting to the point where even in a straight line the TC is cutting in. The ABS light hasn't lit so i'm guessing no faults are stored.

[mnkiboy]

The ABS light did come on this morning, but as OBD2 doesn't include ABS codes it doesn't really help me.

I'll try plugging a multi-meter in to each one and see if I can identify the faulty one. Seems to be intermittent though so might not be easy.