Delving a bit deeper. Even though it has an ABS light, this is not a "real" ABS system. What it appears to be is an electronic limiter valve on the rear brakes only. There is only one sensor, on the rear axle with one pair of solenoids controlling the rear brake line.I suspected as much looking at the valve layout yesterday, I just needed to get under the back and take a look to be sure.
The cable from the rear sensor had a break in it, which I repaired and all is good.
Shaun.