What should I do when a 'Cartridge is low' or 'Cartridge is very low' message appears?

The 'Cartridge is low' or 'Cartridge is very low' message will display on the printer control panel or EWS when toner is running low. You can continue printing until print quality becomes unacceptable, but you should have a replacement cartridge available. Refer to the toner cartridge replacement section for instructions on removing and replacing toner cartridges. (Page 129)