Robert Boschgmbh

Erich Schneider

Eberhard Schnaibel

Erich Junginger

Helmut Fleischer

Frank Blischke

Rudiger Ratzel

Andreas Blumenstock

Lutz Reuschenbach

Martin Klenk

Hong Zhang

Helmut Rembold

Georg Mallebrein

Winfried Moser

Christoph Woll

Klaus Ries-Muller

Andreas Koring

Klaus Hirschmann

Albrecht Clement

Kersten Wehmeier

Rainer Bone

Dieter-Andreas Dambach

Axel Stuber

Bernd Huber

Richard Hotzel

Christian Klinke

Magnus Labbe

Jorg Lange

Alexander Witte

Klaus Hahn

Bernd Heppner

Wolfgang Nonnenmann

Hans P Geering

Wolfgang Richter

Konrad Henkelmann

Manfred Hundhausen

Qiang Qiu

Esfandiar Shafai

Christian Roduner

Rudiger Deibert

René Wackerow

Benno Gerum

Andreas Blumenstook

Klaus Benninger

Peter Doebler

A procedure is introduced to diagnose a catalytic converter system with at least two catalytic converters, through which separate exhaust gas flows flow, with the steps: test if oxygen storage capacities of the catalytic converters, which are at least two in number, exceed a predetermined threshold value. The procedure characterizes itself, in that the oxygen storage capacity of the first of two catalytic converters is compared with at least one first threshold value, in that an additional threshold value is ascertained as a function of a result of the comparison and in that the oxygen storage capacity of the second of two catalytic converters is compared with the additional threshold value. Additionally a control device is introduced, which executes the procedure.

Procedure and control device to diagnose a catalytic converter system of an internal combustion engine

A method for detecting combustion misfires of an internal combustion engine and a device for carrying out the method, in which an evaluation of a lambda signal made available by at least one broadband lambda sensor is provided. The lambda signal is compared to a lambda signal threshold value. A warning signal is made available in response to the exceeding of a threshold in the direction of lean combustion. The procedure especially makes possible the detection of continual misfires which occur, for example, in response to an error in the air supply to the internal combustion engine and/or because of a lack of fuel. The procedure makes possible the detection of dangerous situations for at least one exhaust gas treatment device that is present, which may be removed by introducing protective measures, error warnings and error memory entries.

Method for detecting misfires of an internal combustion engine and device for carrying out the method

A control for diagnosing a catalytic converter in the exhaust gas of an internal combustion engine having means for determining the catalytic converter temperature is presented. The diagnostic method is carried out in dependence upon the catalytic converter temperature. In the diagnosis, only such results are used which have been determined below a threshold value for the catalytic converter temperature.

Method for control of a diagnosis of a catalyst in the exhaust of an internal combustion engine

A method for diagnosing a catalytic converter (), which is arranged in an exhaust-gas system () of an internal combustion engine () has the steps of: detecting the signal (USHK) of an exhaust-gas probe () downstream of the catalytic converter; forming a limit value model amplitude (AHKF) from at least one quantity (ML, n) which occurs upstream of the catalytic converter (); forming a catalytic converter evaluation quantity (DKATI) whose value increases with increasing deviation of the amplitude (AHK) of the signal (USHK) from the limit value model amplitude (AHKF); evaluating the operability of the catalytic converter () on the basis of the catalytic converter evaluation quantity (DKATI); stopping the evaluation when an oxygen-dependent catalytic converter load (KATIN) exceeds or drops below a threshold value. The method is characterized in that the threshold value is pregiven in dependence upon the signal (USHK) of the exhaust-gas probe () rearward of the catalytic converter.

Method and electronic control unit for diagnosing a catalytic converter

An internal combustion engine, especially for a motor vehicle, is described, which is provided with a catalytic converter which can be charged with hydrocarbons. The converting capability of the catalytic converter can be determined by a control apparatus. The converting capability of the catalytic converter is determined by the control apparatus by means of a combination of a passive and an active diagnostic method ( ).

Method for operating and internal combustion engine, in particular of a motor vehicle

The invention is directed to a method for evaluating the operability of a catalytic converter mounted in the exhaust-gas system of an internal combustion engine. In the method, the actual value of a signal of an exhaust-gas probe mounted downstream of the catalytic converter is detected and an expectation value of the signal of the exhaust-gas probe is formed from quantities measured upstream of the catalytic converter. A measure is formed for the deviation of the actual value from the expectation value and the operability of the catalytic converter is evaluated on the basis of the measure.

Method of diagnosing a catalytic converter

The invention is directed to a method of diagnosing a catalytic converter mounted in the exhaust-gas system of an internal combustion engine. An exhaust-gas probe is mounted rearward of the catalytic converter and at least one misfire of a combustion of the engine is stimulated. The reaction of the exhaust-gas probe to the stimulation of the misfire is evaluated to diagnose the catalytic converter. The invention is also directed to an arrangement for diagnosing a catalytic converter.

Method of diagnosing a catalytic converter and arrangement therefor

The invention is directed to a method for adjusting the air/fuel ratio for an internal combustion engine having a catalytic converter connected downstream thereof which is capable of storing oxygen. In this method, the oxygen components in the exhaust gas of the engine are detected upstream of the catalytic converter and downstream thereof and the adjustment of the fuel/air ratio is influenced. In the method, a measure for the instantaneous oxygen fill level of the catalytic converter is determined from the above-mentioned oxygen components with the aid of a model. Data as to the state of deterioration of the catalytic converter are derived from the model parameters. The air/fuel ratio is so adjusted that the oxygen fill level of the catalytic converter is held to a constant mean level.

Method of adjusting the air/fuel ratio for an internal combustion engine

In a method and apparatus for monitoring the operating capability of a catalyzer in the exhaust duct of an internal combustion engine, the operating capability of the catalyzer is assessed on the basis of the increase in temperature produced by the exothermic conversion of the exhaust gases in the catalyzer. The increase in temperature is determined with the aid of two temperature signals, the first temperature signal being produced on the basis of a measurement downstream of the catalyzer and the second temperature signal being formed with the aid of a temperature model. The temperature model may form the temperature downstream of a completely inoperational catalyzer, a catalyzer which is still just sufficiently operational, or a catalyzer which is fully operational. The assessment of the operating capability of the catalyzer is performed on the basis of criteria which are matched to the temperature model used.

Method for monitoring the operating capability of a catalyzer in the

A method for monitoring the starting behavior of a catalytic conversion system by placing an apparatus in the exhaust-gas pipe of an internal combustion engine. The conversion power of the starting region can be determined from the temperature which results when an air/fuel mixture is fed to the catalytic conversion system.

Method and apparatus for monitoring the starting behavior of a catalytic

A method and device for monitoring a heating device of a sensor mounted in the exhaust system of an internal combustion engine. In assessing the working order of the heating device, use is made of the fact that a sensor heated by a heating element heats up more strongly than an unheated sensor, and that it is possible to establish, with the aid of the signals output by the sensor, whether the sensor has exceeded its minimum operating temperature. The temperature of the sensor is simulated as a function of internal combustion engine operating characteristics. The working order of the heating device can be assessed with the aid of the simulated temperature and the information as to whether the minimum operating temperature is exceeded.

Method and device for monitoring a heating device of a sensor mounted in

A method and device for forming a signal relating to a temperature in the exhaust system of an internal combustion engine. The method can be used, for example, to form a signal for the exhaust gas temperature upstream of the catalytic converter, a signal for the temperature in the catalytic converter, or a signal for the temperature downstream of the catalytic converter. The first step is to form a signal for a steady-state exhaust gas temperature as a function of at least one operating characteristic of the internal combustion engine. This signal can be subjected to a series of corrections in order to take into account parameters such as the efficiency of the internal combustion engine, the air/fuel ratio, the temperature of the intake air, the mixture flow rate, the vehicle speed, a possibly activated cylinder cutout, and the presence of condensed water in the exhaust system.

Method for generating a signal relating to a temperature in the exhaust

A method and device for generating a simulated signal relating to a temperature in the exhaust system of a motor vehicle. By means of a characteristic curve or a characteristic diagram, a signal for a steady state exhaust gas temperature is generated as a function of the flow rate of gas through the internal combustion engine of the motor vehicle. This signal is further processed to generate a signal for a rapid portion and to form a signal for a slow portion of the exhaust gas temperature. The signals for the two portions are superimposed with a prescribable weighting to generate a signal for the exhaust gas temperature. The signal for the slow portion can be logically connected, before the superimposition, to a correction value which depends on the speed of the vehicle.

Method for generating a simulated signal relating to a temperature in

System for operating a heating element for a ceramic sensor in a motor

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Kirchheim, Germany

Erich Schneider