Andy..the Hicas is the 4 wheel steer system.
I had a similar thing with the 4wd light and it cured itself after I disconnected the battery.Just on the safe side I got it plugged into the Nissan Diagnostic tool to see if there were any faults and nothing appeared.
If you do disconnect the battery make sure the front wheels are perfectly straight as the Hicas will reset itself when you reconnect..
What I have currently done is checked all the connections and cleaned them. In all fairness there was a lot of dirt on them, and touch wood it has stopped. However, I am thinking of resetting the ECU. Could this cause me more problems than it solves????