摘要:
An electronic control unit performs a process that stores into a buffer selected diagnostic trouble codes (DTC) currently in a volatile trouble code storage by selecting, from among multiple codes, a code that is to be saved in an EEPROM, when an ignition switch of a vehicle is turned off. Further, the DTC stored in the buffer is written in the EEPROM. If the electronic control unit receives, from a scan tool, a command that instructs erasure of the DTC in the volatile trouble code storage, the above-described process is performed before erasing the DTC from the volatile trouble code storage.
摘要:
A vehicular electronic control system includes multiple electronic control units (ECUs) to which a tester is connectable for diagnosis. Each ECU stores a vehicle identifying number (VIN) code that is transmitted to the tester for providing various kinds of information on a vehicle. A priority level is assign to each ECU so that the ECUs transmit the VIN code in order of precedence when the ECU having higher priority is unable to transmit the VIN code when another ECU has not transmitted the VIN code. Moreover, each ECU monitors a communication line when received a VIN code transmission request from the tester and detects an output indicative the VIN code sent from another ECU to the tester. When the ECU has detected the output, it terminates the VIN code transmission and do not transmits the VIN code to the tester.
摘要:
An electronic control unit performs a process that stores into a buffer selected diagnostic trouble codes (DTC) currently in a volatile trouble code storage by selecting, from among multiple codes, a code that is to be saved in an EEPROM, when an ignition switch of a vehicle is turned off. Further, the DTC stored in the buffer is written in the EEPROM. If the electronic control unit receives, from a scan tool a command that instructs erasure of the DTC in the volatile trouble code storage, the above-described process is performed before erasing the DTC from the volatile trouble code storage.
摘要:
A vehicle electronic control apparatus stores vehicle identification information uniquely assigned to a vehicle and vehicle individual information related to the vehicle. When the vehicle identification information is overwritten with new vehicle identification information, it is determined whether the vehicle identification information is equal to the new vehicle identification information. If it is determined that the vehicle identification information is different than the new vehicle identification information, the vehicle individual information is cleared at a time when the vehicle identification information is overwritten with new vehicle identification information. If it is determined that the vehicle identification information is equal to the new vehicle identification information, the vehicle individual information is not cleared at the time when the vehicle identification information is overwritten with new vehicle identification information.
摘要:
A storing area of a non-volatile memory includes a plurality of blocks, in each of which a failure diagnosis frequency (numerator) and an operating frequency (denominator) are stored. The failure diagnosis frequency is the number of times failure diagnosis is executed, while the operating frequency is the number of times a vehicle enters a given operating state. When the vehicle enters the given operating state or the failure diagnosis is executed, rewriting is executed as incrementing, by one, the stored failure diagnosis frequency or operating frequency in a given block. When the operating frequency in the given block reaches an overflow threshold, the failure diagnosis frequency and operating frequency are reduced to half and written in a different block.
摘要:
A vehicle electronic control apparatus stores vehicle identification information uniquely assigned to a vehicle and vehicle individual information related to the vehicle. When the vehicle identification information is overwritten with new vehicle identification information, it is determined whether the vehicle identification information is equal to the new vehicle identification information. If it is determined that the vehicle identification information is different than the new vehicle identification information, the vehicle individual information is cleared at a time when the vehicle identification information is overwritten with new vehicle identification information. If it is determined that the vehicle identification information is equal to the new vehicle identification information, the vehicle individual information is not cleared at the time when the vehicle identification information is overwritten with new vehicle identification information.