ok, so the obvious cause of this is the cable is damaged or not fully plugged in. i have disconnected and reconnected several times and still get this error.
I opened the pool a few days ago with the dummy cell in place during the initial clean up. once the water was above 60 deg, i installed the cell which gave me a low salt indication (which i expected). over the course of the day, i gradually added 8 40lb bags of salt. the easytouch panel under the diagnostic menu told me i went from 1650ppm to 2650ppm. a few hours after the last 2 bags were added i came back to this error, and have had it since.
so i am tempted to muck around with the pins...ie bend them slightly, or put an electronics type cleaner on them. and perhaps reinstall the dummy cell and see if i can check the cord connections in the cell.
i have been in contact with Pentair. They are currently reviewing. I purchased the easytouch with intelichlor, intelibrites, inteliflo and cartridge filter in july 2011 and the swg went into service in may of 2012. (build date is 30/11/11). Since i bought 3 or more pieces at once, they may warranty it, but i'm curious if anyone has run into this and if there is a possible fix that could save the cell.
thanks in advance