CAR DIAGNOSING DEVICE CONTAINING STUDY CONTROL SYSTEM

摘要

PURPOSE:To obtain a result of diagnosis with high reliability and to reduce misdiagnoses, by rewriting the standard value for diagnosis by the information on a study system. CONSTITUTION:For a study control system 30, an initialization pattern storage device 31 stores an optimum ignition advance angle pattern based on conditions of input given from sensors 38 and 39. The ignition advance angle value is compared with the advance angle value stored in a nonvolatile memory 37 through an ignition advance angle arithmetic circuit 32. Then an ignition driving circuit is actuated by the result of comparison. A knocking sensor 35 detects the knocking phenomenon of an engine 34 and supplies the detecting signal to an ignition delay angle arithmetic circuit 36. The circuit 36 processes the input signal and calculates both ignition advance and delay angle values which show the knocking limit to store the result of operation to the memory 37. A microcomputer 42 of a diagnosis standard value storage circuit 40 fetches the information from the memory 37 and rewrites the contents of a standard value storage circuit 41 into the value obtained by the study system. A diagnosing device 50 diagnoses a car on the basis of the standard value corresponding to the study of the circuit 41.