초록 ▼

A positive crankcase ventilation system diagnostic applied in an automotive internal combustion engine with a pressure sensor disposed in the system for continuous sensing of system pressure while the engine is running in a steady state operating condition, with minimum and maximum sensed pressure v

A positive crankcase ventilation system diagnostic applied in an automotive internal combustion engine with a pressure sensor disposed in the system for continuous sensing of system pressure while the engine is running in a steady state operating condition, with minimum and maximum sensed pressure values stored during each of repeated test periods. Pressure values exceeding a predetermined normal range over at least one test period indicate a leak or restriction condition in the system. Small differences in pressure values over test periods indicate sensor or electrical fault conditions. Fault conditions are logged and are indicated if persistent.

대표청구항 ▼

[ The embodiments of the invention in which a property or privilege is claimed are described as follows:] [1.] A method for diagnosing fault conditions in an internal combustion engine crankcase ventilation system, comprising the steps of:transducing crankcase pressure into a pressure signal;repeate

[ The embodiments of the invention in which a property or privilege is claimed are described as follows:] [1.] A method for diagnosing fault conditions in an internal combustion engine crankcase ventilation system, comprising the steps of:transducing crankcase pressure into a pressure signal;repeatedly sampling the pressure signal over a test period;storing a maximum sampled pressure;storing a minimum sampled pressure;comparing the maximum sampled pressure to a high pressure threshold following the test period;diagnosing a fault condition when the maximum sampled pressure exceeds the high pressure threshold;comparing the minimum sampled pressure to a low pressure threshold following the test period; anddiagnosing a second fault condition when the minimum sampled pressure is less than the low pressure threshold.