A little unusual fault maybe? But interesting.
The electrical cable had been fitted incorrectly to the point where the suspension had completely severed the wire.
I've got the old sensor part here and just ordered a used replacement off eBay for £15.
The previous owner said he had a stearing part replaced on the nearside for the new MOT which was new when I bought the car.
Whoever fitted the stearing component got the abs wire wrapped around the suspension and had not thought about the routing of the wire in the reassembly. As it had not been driven since the new MOT and when we bought it, the ABS wire was severed fairly soon after.
Good result in a way, at least it is nothing major.

I've just bought my own "OBD II ELM327 Pro" scanner V2.1 with blue tooth android interface.