Hmm I'm sure I read in the nissan manual or somewhere that that electrical plug on the k11 hydraulic power steering is to tell the ECU when to raise the idle etc. Its for when you have the steering under load at idle, that sensor picks that up, and the ECU raises idle.
The guy off Autospeed intercepted the torque sensors off his EPS system (on Toyota Prius), to tell the system that the torque sensors were reading different figures than they actually were. Resulted in him having a fair bit of control over the steering feel.
I love the feel of my super-s non power steering when driving around and for handling, but it would be quite cool to have something like this kick in below say 40kmh, make parking easier etc.