A method for analyzing a fluid that flows from a chamber, in particular a combustion chamber, of an internal combustion engine into a fluid guide. The internal combustion engine includes at least one element, in particular an injector, for the supply of fuel. The analysis takes place with the aid of a sensor, in particular a lambda sensor, on which the fluid in the fluid guide acts. The analysis takes place during cranking of the internal combustion engine, and the fluid acting on the sensor is not influenced by fuel that is supplied in a controlled manner.

Methods and systems are provided for accurately inferring an exhaust temperature during steady-state and transient vehicle operation based on the duty cycle of an exhaust gas sensor heating element. A steady-state temperature is inferred based on an inverse of the duty cycle, and then adjusted with a transfer function that compensates for transients resulting from changes in vehicle speed, and load, and for the occurrence of tip-in and tip-out events. The inferred temperature can also be compared to a modeled temperature to identify exhaust temperature overheating conditions, so that mitigating actions can be promptly performed.

Methods and systems are provided for adjusting heater power of an oxygen sensor. In one example, a method for an engine includes adjusting heater power of a heating element of the oxygen sensor when the heater power increases by a threshold amount. The method includes subsequently increasing heater power back to a baseline power level responsive to a temperature of the heating element.

The present disclosure relates to a system, apparatus, and method for reconditioning a particulate matter sensor in an exhaust aftertreatment system that will resist poisoning. The system and method includes receiving particulate matter data indicating a state of the particulate matter sensor; determining that the particulate matter sensor is in a full state based on the particulate matter data; activating a heating element of the particulate matter sensor to a multiple of intermittent temperatures that clean the sensor pre-patory to the next measurement. By this manner, many reactive chemicals are removed before they can react with and poison the sensor materials.

A control circuit includes a sweep circuit for supplying a sweep current to a gas concentration sensor, a current detection resistor for detecting a sensor current flowing in the gas concentration sensor, a calculation circuit for calculating an impedance of the gas concentration sensor based on the sensor current and an inter-terminal voltage of the gas concentration sensor, and a protective element for suppressing external noise from being applied to the sweep circuit and the calculation circuit. The sweep current is divided to flow in a first protective element and the gas concentration sensor. The sensor current is divided to flow in a second protective element and the current detection resistor. The calculation circuit calculates a loss current flowing to the first protective element or a second loss current flowing to the second protective element and calculates the sensor current based on the calculated current.

A method of oxygen sensor heater control includes: exhausting an exhaust gas by operating an internal combustion engine; and stopping operation of the engine such that the exhaust gas is not discharged. The stopping operation of the engine includes heating a sensor element by operating a heater that is positioned adjacent to the sensor element, and the sensor element is configured to detect a characteristic of the exhaust gas.

Methods and systems for estimating engine exhaust gas temperature and adjusting engine operation based on the engine exhaust gas temperature are disclosed. In one example, an offset value for a resistive heating element of an oxygen sensor is determined so that the resistive heating element may be a basis for providing accurate engine exhaust gas temperatures.

A control device selectively executes first and second energization control for controlling an energization amount to the heater. The first energization control is executed to keep temperature of a sensor element within an active temperature region. The first energization control is PWM control in which the energization amount is controlled with closed loop control such that an impedance of the sensor element matches a target value. The second energization control is PWM control in which the energization amount is controlled with open loop control so as to keep the temperature of the sensor element within a preset temperature region that is lower than the active temperature region. The control device executes the second energization control during an internal combustion engine is stopped while executing the first energization control during the internal combustion engine is not stopped.

A control device for an exhaust sensor is configured to control the exhaust sensor disposed in an exhaust passage of an internal combustion engine. The control device for an exhaust sensor includes: a sensor element; a heater configured to heat the sensor element; a current detection circuit configured to detect an output current of the exhaust sensor, and an electronic control device configured to control electric power that is supplied to the heater by PWM control.

To provide a sensor control device capable of identifying a short circuit terminal with a simple configuration and whose identification operation is not easily affected by environmental conditions around the sensor. The sensor control device includes a short circuit detection unit that detects a short circuit of a sensor having a plurality of terminals, a resistance value control unit that increases a resistance value of an element between the terminals when the short circuit of the sensor is detected by the short circuit detection unit, and a short circuit terminal identification unit that identifies at which of the plurality of terminals a short circuit occurs when the resistance value control unit increases the resistance value of the element between the terminals to a set value or greater.