the Hicas is infact 'electronic'......... .. ..
Look I've had the same issue for a while now, we have confirmed, all power steering mechanical and hydrolic elements are working properly. The issue is intermittent like yours aswell, (light on + steering heavy), and it also does it now and then.
I have been searching these forums for my old thread, but have been unable to find it.
Ive made numerous phone calls, spoken to all types of work shops, on this matter. Including a fair few suspension specialists. and No one has any idea of the cause, and no one has nessesary tools or equipment to diagnose hicas issues. Our only hope may be in Japan.
If you find anyone in australia who does please let me know. As I would like to keep my hicas working.