All Canon printers have a built-in sensor that can tell how much ink is inside each ink cartridge. This can be a problem if you have a little bit of ink left, since a "low ink" message effectively disables the printer until you change the cartridge. "Low ink" readings also occur when you refill Canon cartridges. Each Canon printer has a different way of resetting the ink counter, so follow the instructions for your specific printer model.
Turn off the printer and unplug the power cable.
Press down on the "Power" button and plug the cable back in while still holding down the button.
Tap the "Cancel/Stop" button twice while holding the "Power" button down.
Lift your finger off the "Power" button. Wait 30 seconds for the printer display to read "Idle."
Use the printer arrows to select "Shipping Mode" and press "OK."
Tap the "Power" button and wait for the test page to print.
Lift up the printer cover and unplug the printer.
Remove the ink cartridges inside and close the printer cover.
Plug the printer back in and tap the "Power" button.
Lift up the cover and insert the ink cartridges back inside.
Turn off the printer. Hold down the "Resume" button and then press "Power."
Let go of the "Resume" button while still pressing down "Power."
Tap the "Resume" button twice while holding down "Power." Then release the "Power" button.
Click "Resume" four times in a row and then tap "Power" once.
Power off the printer and restart it.