Abstract:
The invention relates to a method and device for diagnosing deviations in a single cylinder lambda control in an internal combustion engine having at least two cylinders and an exhaust gas sensor designed as a broadband lambda sensor, wherein a pump current is evaluated by means of a pump cell and the pump current is used at least temporarily for an individual cylinder lambda control. According to the invention, a pump voltage or a pump voltage change is determined via the pump cell in addition to the pump current and the value is transmitted to a diagnosis apparatus. Deviations in the single cylinder lambda control can thus be better diagnosed without additional material expense according to the invention, which provides advantages in particular in respect of tightened rulemaking in on-board diagnosis. A preferred application of the method is the use in internal combustion engines having multi-bank exhaust systems.
Abstract:
A method for diagnosing and/or adapting at least one system (12, 14) of a device (10) is described, which method comprises the following steps: (a) at least one manipulated variable (44) of at least one system (12, 14) of the device (10) is changed with respect to a currently present value of the manipulated variable (44); (b) at least two state variables (46) of at least one system (12, 14) are determined; (c) a decision (61) about the further execution of the method is made as a function of the at least two state variables (46).
Abstract:
A method for diagnosing and/or adapting at least one system (12, 14) of a device (10) is described, which method comprises the following steps: (a) at least one manipulated variable (44) of at least one system (12, 14) of the device (10) is changed with respect to a currently present value of the manipulated variable (44); (b) at least two state variables (46) of at least one system (12, 14) are determined; (c) a decision (61) about the further execution of the method is made as a function of the at least two state variables (46).
Abstract:
A circuit configuration for operating a gas sensor is described, including a reference gas space in which an electrode is situated which is supplied with a reference gas pump current to maintain the concentration of the reference gas. A diagnostic system determines a concentration change of the reference gas via a change in the reference pump current and a time-based evaluation of the sensor signal of the gas sensor.
Abstract:
A method for diagnosing the dynamic characteristics of a lambda sensor, which is used at least intermittently for a cylinder-individual lambda closed-loop control, which provides for at least one actuating variable of the lambda closed-loop control to be detected and compared to a specifiable maximum threshold, and, if the maximum threshold is exceeded, the dynamic response of the lambda sensor is deemed insufficient with respect to the usability for the cylinder-individual lambda closed-loop control.
Abstract:
A procedure for detecting manipulations at lambda comprises the following steps; the lambda probe is excited by at least one electric excitation signal; at least one electric response signal of the probe is detected; the at least one response signal is compared to at least one default electric response signal that characterizes a not manipulated probe; the deviation of the detected at least one electric response signal from the at least one default electric response signal is used for detecting a manipulation of the probe. A device for detecting manipulations at lambda probes characterized by a switch assembly, with which the probe can be impinged with an electric excitation signal, in particular a step-wise electric excitation, preferably with a current impulse, by a evaluation switch device for evaluating a response signal, in particular the probe voltage and for comparing the excitation signal with the response signal and for assuming a manipulation in the case of a deviation of the response signal from a response signal that characterizes a not manipulated probe.
Abstract:
A method for diagnosing the dynamic characteristics of a lambda sensor, which is used at least intermittently for a cylinder-individual lambda closed-loop control, which provides for at least one actuating variable of the lambda closed-loop control to be detected and compared to a specifiable maximum threshold, and, if the maximum threshold is exceeded, the dynamic response of the lambda sensor is deemed insufficient with respect to the usability for the cylinder-individual lambda closed-loop control.
Abstract:
A method for influencing the exhaust gas temperature of an internal combustion engine is described in which measures can be carried out for increasing, lowering and limiting exhaust gas temperature. Depending on temperature requirements, and in which method these temperature requirements are prioritized, the temperature limitation having the highest priority for ensuring protection of the component parts, the resulting temperature requirement may be achieved by heating measures or cooling measures in such a way that heating measures and cooling measures are not applied at the same time.
Abstract:
An internal combustion engine (1), especially for a motor vehicle, is described, which has a three-way catalytic converter (12″) and a storage catalytic converter (12′) which can be loaded with and unloaded of nitrogen oxides. A diagnosis of the storage catalytic converter (12′) is carried out by a control apparatus (18) below a temperature at which the three-way catalytic converter (12″) does not yet operate.
Abstract:
A procedure for detecting manipulations at lambda comprises the following steps; the lambda probe is excited by at least one electric excitation signal; at least one electric response signal of the probe is detected; the at least one response signal is compared to at least one default electric response signal that characterizes a not manipulated probe; the deviation of the detected at least one electric response signal from the at least one default electric response signal is used for detecting a manipulation of the probe. A device for detecting manipulations at lambda probes characterized by a switch assembly, with which the probe can be impinged with an electric excitation signal, in particular a step-wise electric excitation, preferably with a current impulse, by a evaluation switch device for evaluating a response signal, in particular the probe voltage and for comparing the excitation signal with the response signal and for assuming a manipulation in the case of a deviation of the response signal from a response signal that characterizes a not manipulated probe.