Patent ID: 8898032

Claim:
A method for estimating a temperature of an exhaust gas in an exhaust line of an internal combustion engine, the exhaust line comprising a NO x sensor that comprises an heater, the method comprising: determining, with an electronic control unit (ECU), a value of a parameter indicative of an heat released by the heater of the NO x sensor; and calculating, with the electronic control unit (ECU), a value of the temperature of the exhaust gas as a function of the value of the parameter, wherein the parameter is an electrical power supplied to the heater of the NOx sensor, and wherein the value of the parameter is calculated according to: P el = dc · V batt 2 R H , wherein, P el is the value of the electrical power supplied to the heater of the NO x sensor, wherein V batt is a value of a voltage supplied by an electrical battery connected to the heater of the NO x sensor, wherein dc is a duty cycle of a PWM electrical signal generated with the electrical battery and supplied to the heater of the NO x sensor, and wherein R H is a value of an electrical resistance of the heater of the NO x sensor.