There is a menu option in the printer that enables override of the consumables.
From the printers control panel go to System setup -> Print Quality -> Replace supplies -> Select Override out.
Beware that overriding the printers toner out message can cause severe print defects and/or printer hardware malfunction.
Explanation :
The toner usage count is based on two things :
1) Amount of toner left in the cartridge.
2) The numbers of times the cartridge has rotated.
The printer might report the toner to be out while there is still toner left in the cartridge. The toner out message is calculated by the number of rotations made and the amount of toner left in cartridge. The toner out message is a sort of alert to the user, that he/she might experience print defects if continuing using the cartridge.
Lots of small printjobs will wear more on the cartridge than a few large printjobs because the printer often has to calibrate between the small jobs, thereby causing wearness to the cartridge by the rotation of the cartridge.