Patent ID: 8095264

Claim:
A vehicle-mounted information system, comprising: a plurality of ECUs that transmit/receive control information to/from each other for controlling a vehicle over an in-vehicle network; a device under the management and control of the ECUs; and a diagnostic equipment that gathers, for accumulation, the control information from the network through coupling thereto, wherein the diagnostic equipment includes: means for determining whether the vehicle is defective or not based on the control information gathered from the network; means for making an inquiry to each of the ECUs coupled to the network whether or not there is a memory for temporarily logging information for use with a control-target device thereof; and means for creating, when the vehicle is determined as being defective, a defect notification message with respect to any of the ECUs whose response against the inquiry is “yes”, and transmitting the message to the network, and the ECUs each include: means for managing internal information indicating whether a memory area can be reserved for logging the information for use with the device under the management and control of its own; means for forwarding back the internal information to the diagnostic equipment in response to the inquiry coming over the network to see whether there is the memory; means for accumulating, in the memory of its own, when the internal information includes information telling that “there is the memory area”, the information to be transmitted/received to/from the control-target device of its own; and means for stopping, when the defect notification message is provided, after accumulating the information for use with the control-target device thereof for a predetermined length of time, the accumulation thereof.