Rover 620 sli ABS?

I am trying to find why the ABS light comes on after only a few miles. Before I use to be able to drive 30 or 40 miles. I have cleaned to sensors but still the light still comes on. I have read there is often a way to extract the fault codes by bridging a connection, normally under the steering column. Some mention 2 pin plugs some mention 4 pin plugs. Does anyone know exactly where the wires are and what they look like.
Any help would be much appreciated.