초록 ▼

A system for diagnosing an internal combustion engine having engine operation sensing devices. A diagnosing circuit is provided to response to output voltages of the sensing devices for producing a first signal when the voltage exceeds a predetermined range and a second signal with a delay after the

A system for diagnosing an internal combustion engine having engine operation sensing devices. A diagnosing circuit is provided to response to output voltages of the sensing devices for producing a first signal when the voltage exceeds a predetermined range and a second signal with a delay after the first signal. A fail-safe signal generating circuit is provided to produce one of fail-safe signals in dependency on the first signal so as to prevent the stall of the engine. The second signal operated to indicate trouble in the engine operation sensing devices after the fail-safe operation.

대표청구항 ▼

A system for diagnosing an internal combustion engine comprising: an engine operation sensing device; a diagnosing circuit including a window comparator for producing a first output signal when the output of said sensing device exceeds one of predetermined limit values, and first and second circuit

A system for diagnosing an internal combustion engine comprising: an engine operation sensing device; a diagnosing circuit including a window comparator for producing a first output signal when the output of said sensing device exceeds one of predetermined limit values, and first and second circuit means operatively coupled to said window comparator, said first circuit means producing a second output signal when the first output signal of said comparator continues for a first predetermined time, said second circuit means producing a third output signal when the first output signal continues for a second predetermined time longer than the first predetermined time; a fail-safe signal generating circuit producing a fail-safe signal; switch means responsive to said second output signal of said first circuit means for allowing the fail-safe signal to pass from said fail-safe signal generating circuit; means responsive to said fail-safe signal for producing a quasi signal to maintain the operation of the engine; and an indicator means responsive to said third output signal for indicating trouble in said engine operation sensing device.