Patent ID: 8407986

Claim:
A method for operating at least one lambda sensor arranged in an exhaust gas system of an internal combustion engine during a start and heating phase comprising a lambda control system for controlling the fuel/air mixture ratio of a combustion process of the internal combustion engine, wherein the exhaust gas system has at least one catalytic converter and assigned to the lambda sensor is at least one electric heating element for heating up the lambda sensor to an operating temperature and the heating-up of the heating element is carried out by means of a heating element control, wherein control parameters are predetermined for the lambda control system, that the method comprising: substantially synchronous with the start of the internal combustion engine, charging the heating element with a predefined heating power; during the heating, detecting a signal of the lambda sensor and comparing the detected signal to a predetermined threshold value for at least one of a lean fuel/air mixture ratio and a rich fuel/air mixture ratio, which correlates with a temperature value of the lambda sensor which is below a water ingestion critical temperature and at the same time conforms to a valid lambda signal; at a first-time arrival of the lambda signal at one of the predetermined threshold values, triggering a determination of a measurement variable correlating with the temperature of the lambda sensor and forwarding the lambda signal, identified as valid, for a further utilization; and transferring the determined measurement variable correlating with the temperature of the lambda sensor to a closed heating element control loop as a reference value corresponding to a reference temperature.