Patent ID: 6332459
Filing Date: 2001-12-25
Classification: F02D

Abstract:
A system for controlling a temperature of a heater of an air-fuel ratio sensor installed in an internal combustion engine and generating a signal indicative of an air/fuel ratio in an exhaust gas generated by the engine; including;the heater installed at the air/fuel ratio sensor and for heating a sensing element of the air/fuel ratio sensor when supplied with current; andcurrent supply control means for controlling a supply of current to the heater;wherein the improvement comprises;the engine is a direct injection spark ignition engine which is operated at an ultra-lean burn combustion or at a pre-mixture charged combustion; and,the system includes:sensor temperature determining means for determining the temperature of the air-fuel ratio sensor; andcombustion determining means for determining whether the engine is operated at the ultra-lean burn combustion;and the current supply control means controls the supply of current to the heater based at least on the determined temperature of the air-fuel ratio sensor and a result of determination whether the engine is operated at the ultra-lean burn combustion.