| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve the accuracy of diagnosing of communication trouble for vehicle communication systems. <P>SOLUTION: An engine ECU transmits a test signal including a time stamp T to a diagnosis target ECU (S130), and determines whether or not to receive a reply signal of the test signal (S140). If not receiving (S140:NO), the engine ECU determines whether or not to be time-out (S150), and then if not time-out (S150:NO), the processing is returned to the step S140. When receiving a replay signal (S140:YES), the engine ECU determines whether or not a time stamp T of the previous test signal matches to a time stamp T of the reply signal (S160). If they do not match (S160:NO), the processing is returned to the step S140. If it is time-out (S150:YES), an error counter E is incremented by one (S170), and the time stamp T is incremented by one for every test signal transmission (S120). If the time stamp T reaches a specified number (S175), communication troubles are diagnosed based on E/T (S180 to S190). <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
