| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To detect power source retaining abnormality and power source shut-off abnormality by an electronic control device. <P>SOLUTION: ECU for a vehicle is provided with power source retaining function in which when at least one of an ignition switch and a key switch is turned ON, a relay for feeding electricity is turned ON and a power source voltage is fed to a micro-computer and even if both switches are turned OFF, the ON state of the relay is continued until the micro-computer completes specific processing and a power source retaining signal is made low. The micro-computer measures a power source retaining time from when both switches are turned OFF to stopping of operation by counting up a counter value CT in a flash ROM by processing in every fixed time and when it detects that any one of both switches is turned ON (S310; YES), if the counter value CT is smaller than a first determination value HA, it determines as power source retaining abnormality (S320: YES) and if the counter value CT is larger than a second determination value HB, it determines as power source shut-off abnormality (S360: YES). <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
