초록 ▼

An air/fuel ratio control system equipped with a temperature sensor fail-safe system for an internal combustion engine, comprises an engine parameter detecting circuit for the estimation whether the engine coolant temperature sensor is normal or not, a constant voltage supply, and a switching circui

An air/fuel ratio control system equipped with a temperature sensor fail-safe system for an internal combustion engine, comprises an engine parameter detecting circuit for the estimation whether the engine coolant temperature sensor is normal or not, a constant voltage supply, and a switching circuit for transmitting the constant voltage to a control signal generator, in place of the output signal of the engine coolant temperature sensor, the control signal generator generating a control signal in accordance with various engine parameters including the engine temperature for the control of the air/fuel ratio of an air/fuel mixture supplied to the engine, thereby providing the control signal generator with a suitable signal when a failure occurs in the engine coolant temperature sensor to prevent undesirable operation.

대표청구항 ▼

In an air/fuel ratio control system for an internal combustion engine, including sensors for detecting engine parameters, said sensors including an engine temperature sensor for producing an output signal indicative of the engine temperature, a control signal generator responsive to the detected eng

In an air/fuel ratio control system for an internal combustion engine, including sensors for detecting engine parameters, said sensors including an engine temperature sensor for producing an output signal indicative of the engine temperature, a control signal generator responsive to the detected engine parameters, and one of a fuel supply mechanism and air/fuel mixture supply mechanism responsive to a control signal from said control signal generator for supplying one of fuel and air/fuel mixture to said engine; wherein the improvement comprises: (a) first means for providing an engine parameter signal indicative of the engine temperature; (b) second means for detecting whether said engine temperature sensor is in a normal or abnormal operative condition in view of said engine parameter signal; (c) third means for producing a predetermined voltage having a magnitude which corresponds to a voltage of the output signal of said engine temperature sensor under conditions of normally high temperatures; and (d) fourth means for selectively transmitting the output signal of said engine temperature sensor and said predetermined voltage in accordance with a normal or abnormal condition of said engine temperature sensor detected by said second means.