ELECTRONIC CONTROL DEVICE

PROBLEM TO BE SOLVED: To provide an electronic control device which can be restored even if a CPU runs away during diagnosis, only if a watchdog timer operates normally, by diagnosing the watchdog timer without performing switching to a reset signal port. SOLUTION: The CPU 2 performs fault diagnosis of the watchdog timer 3 by determining whether or not the watchdog timer 3 has been reset with respect to the CPU 2, when a P-RUN signal supplied from the CPU 2 to the watchdog timer 3 stops. During the resetting, because the CPU 2 writes eta in an EEPROM 5 prior to the stop of the P-RUN signal, determination as to whether or not the watchdog timer 3 has been reset is made using data written in the EEPROM 5. COPYRIGHT: (C)2005,JPO&NCIPI