EBME Forums Forums Maintenance Technical Assistance Ivac 572 extender loom - Constant 'FIX ME 3'

I remove the main battery when I connect the loom then I reconnect the battery. Usually you initially get the Fix me 3 and then you turn off/turn on with the battery connected and the Fix me 3 doesn't reappear. Recently the Fix me 3 remains!
I have successfully calibrated lots of pumps using this method in the past but now I have this problem.