We get that error when air pressure is low,or is there is a little rust on the tool holder preventing the drawbarfrom releasing the tool(we live in a high humidity area and things seem to rust while the shop closesfor the weekend). I often fix it by manually removing tool and cleaning it with some scotchbrite and I also clean the spindle with the scotchbrite if rust is present.
If the air pressure is good and the toolholder is clean, the drawbar up sensor may need to be adjusted or replaced. Does it do it on all of your tools or is it just one tool? Call us here at Thermwood and we can help you get it straightened out. You can also contact CNC Automation in Canada. 1 800 221 3865 or for CNC Automation 1 800 421 5955.