Robert Boschgmbh

Bernhard Schmidt

Ulrich Drews

Peter Werner

Michael Horbelt

Manfred Mezger

Hans Schnurle

Gerhard Sohner

Herman Roozenbeek

Karl Seeger

To permit continued operation of a vehicle in spite of malfunction of an electronic ignition computer system, or any other electronic control module in an automotive vehicle, a transducer (10) provides an output to a trigger stage which has its output connected a digitally operating microprocessor (17) and to a bypass or transfer switch (21). The output from the microprocessor is connected to an analog and operating output stage (19, 20) to be controlled by the digital system of the microprocessor (17). Upon sensing of low operating voltage (U) as determined, for example, by a threshold switch (22), or of starting condition the switch (21) is closed, bypassing or interrupting connection to the microprocessor, and directly connecting signals from the transducer output stage to the input of the ignition circuit to permit operation under emergency conditions. The analog portion of the system is a single integrated module, separate from the digitally operating microprocessor (17) for ease of error diagnosis, maintenance and repair. This is particularly important with digitally operating control systems (17) which are subject to malfunction under low voltage conditions or upon occurrence of stray or distrubance signals in the network, for example under starting conditions.

Electronic engine control system with emergency operation mode

This invention relates to an apparatus for controlling at least one electrical switching element in internal combustion engines, particularly the main relay of the voltage supply, in accordance with one operating characteristic and with a switch position which indicates an operating condition, in which the signal corresponding to the operating characteristic can be fed to a storage device whose charging and/or discharging process can be influenced by the switch relative to the ignition with the value of the storage signal serving to control the electrical switching element. Furthermore, the signal in accordance with the operating condition and, indirectly or directly, corresponding to the operating characteristic can be fed to a connection point whose output signal can be switched to a switching device for heating the heating wire in an air flow rate meter to a red-hot condition.

Apparatus for controlling an electrical switching element in internal

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Leonberg, Germany

Bernhard Schmidt