An ice maker assembly is disposed in the ice compartment of a refrigerator, the ice maker assembly including an ice maker tray/evaporator having an evaporator cooling tube which is in direct contact with an ice maker tray portion, and a tray temperature sensor for sensing a temperature of the ice maker tray portion. A controller is configured to control ice making, ice harvesting, and ice maintenance based on the temperature sensed by the tray temperature sensor. The tray temperature sensor is the only temperature sensor used to control ice making, ice harvesting, and ice maintenance. Alternatively, an additional temperature sensor can be disposed inside an ice maker assembly gear box for sensing a temperature of a housing of the gear box. In that case, the tray temperature sensor and the additional temperature sensor are the only temperature sensors used to control ice making, ice harvesting, and ice maintenance.