R32 Power Steering / Hicas Woes

[dark.sky]

Hey guys, I have a R32 GTSt and have just finished installing a RB25DET. With the RB20, the HICAS light never came on (well, it would if you started the car and didnt move it for 10 minutes) and the power steering worked fine. With the 25, I start the car, HICAS light goes off immediately as it always did, and the steering feels great. After about 5 minutes of driving the steering goes very heavy, and the HICAS light comes on moments later. It wont go off unless you turn the car off and start it again, but this just re runs the cycle. My speedo works fine (have a mechanical sender on the RB25 box), and there is sufficient fluid. Steering wheel was not removed.

Questions:

Is it possible to have HICAS + Speed Sensitive Steering working on a 25'd 32?

Would air in the system cause this?

Would damage to a line (slightly squashed) cause this?

I tried today to get it into the HICAS Diagnostic Mode, with no success.

Cheers in advance guys, I have searched, but my main question is can the steering function as normal with a 25, because if the answer is no, Im just chasing false hopes haha.