Methods and systems are provided for water injection into an engine and adjusting engine operation based on engine dilution demand and engine knock. In one example, a method may include injecting water into an intake manifold via a port water injector or a manifold water injector and adjusting engine operation. Further, the method may include adjusting engine operation based on a change in engine dilution or knock.

A heating device for a drive unit in a motor vehicle includes at least one heating element and at least one sensor by means of which a predetermined behavior of the vehicle user preceding the start of the drive unit can be detected. The sensor interacts with the heating element in such a manner that it is switched on when the sensor detects the predetermined behavior. The predetermined behavior may be one or more of the following: inserting an ignition key in an ignition lock of the motor vehicle; actuating a shifting, clutch or braking device of the motor vehicle; or a behavior through which an anti-theft device of the motor vehicle can be triggered.

An automatically stoppable internal combustion engine comprises an exhaust purification catalyst, an upstream side air-fuel ratio sensor, a downstream side air-fuel ratio sensor, and sensor heaters heating air-fuel ratio sensors. A controller comprises an air-fuel ratio control part and a heating control part. The heating control part controls the temperature of the upstream side air-fuel ratio sensor to the activation temperature or more and the temperature of the downstream side air-fuel ratio sensor to less than the activation temperature during automatic stop of the internal combustion engine. The air-fuel ratio control part controls the air-fuel ratio of the exhaust gas based on the outputs of the two air-fuel ratio sensors during engine operation and controls the air-fuel ratio of the exhaust gas temporarily based on the output of the upstream side air-fuel ratio sensor without using the output of the downstream side air-fuel ratio sensor.

Various methods are provided for compensating changes in the relation between impedance setpoint and operating temperature in an oxygen sensor. In one embodiment, a method of operating an oxygen sensor comprises adjusting an impedance setpoint based on a change in dry air pumping current of the oxygen sensor.

A method for monitoring an exhaust-gas sensor in which it is determined whether at least one monitored event has occurred by evaluating at least one heat quantity supplied to and/or withdrawn from the exhaust-gas sensor during a period of time, in particular under consideration of a change in the heat quantity stored by the exhaust-gas sensor that occurs during the period of time.

An abnormality diagnosis system of limit current type air-fuel ratio sensors comprises a current detecting part and a sensor temperature control device. The abnormality diagnosis system uses the current detecting part to detect the output current of the air-fuel ratio sensor when the air-fuel ratio is made the rich air-fuel ratio in the state where temperature of the air-fuel ratio is made the first temperature and when the air-fuel ratio is made the rich air-fuel ratio in the state where the temperature of the air-fuel ratio is made a second temperature higher than the first temperature. It is judged that the air-fuel ratio sensor is abnormal if the output current when the temperature of the air-fuel ratio sensor is the first temperature is larger than the output current when it is the second temperature by a predetermined value or more.

A direct fuel injection internal combustion engine fluidly coupled to an exhaust aftertreatment system is described and includes a plurality of fluidly coupled exhaust purifying devices and an exhaust gas sensor. A method of controlling the engine includes, activating, via a heater controller, a heating element of the exhaust gas sensor in response to starting the internal combustion engine. An exhaust gas feedstream is monitored to determine a temperature of the exhaust gas sensor. Engine control to effect heating of one of the exhaust purifying devices is permitted only when a temperature of the exhaust gas sensor is greater than a threshold temperature.

Various methods are provided for compensating changes in the relation between impedance setpoint and operating temperature in an oxygen sensor. In one embodiment, a method of operating an oxygen sensor comprises adjusting an impedance setpoint based on a change in dry air pumping current of the oxygen sensor.

For diagnosing a proper functioning of an auxiliary heater in an air mass sensor in an engine system including an internal combustion engine, the auxiliary heater being used for preventing contamination of a sensor area, the air mass sensor communicating air mass information via a signal line during a sensor operating mode and, if a specified state on the signal line is detected, activating the auxiliary heater, the following are performed: setting the state of the signal line to the specified state for a predefined time period in an auxiliary heater operating mode; transmitting a first temperature information before the activation of the auxiliary heater operating mode and a second temperature information via the signal line after expiration of the predefined time period; and detecting the proper functioning of the auxiliary heater depending on the difference between the first temperature information and the second temperature information.

A particulate detection device has an insulation part, electrodes, an adhesion amount calculation section, a heater and a controller. The insulation part is located in an exhaust passage of an internal combustion engine and has an adhesion surface to which exhaust particulates emitted from the internal combustion engine adhere. The adhesion amount calculation section calculates an adhesion amount of the exhaust particulates adhered to the insulation part based on an electrical resistance between two of the electrodes. The controller, in a normal control, controls an air/fuel ratio in the internal combustion engine to be a theoretical air/fuel ratio. The controller, in a regeneration control, controls the heater to increase a temperature of the insulation part and removes the exhaust particulates from the insulation part by burning the exhaust particulates, and controls the air/fuel ratio to be lean as compared to the theoretical air/fuel ratio.