ELECTRIC POWER STEERING DEVICE

PROBLEM TO BE SOLVED: To provide an electric power steering device capable of surely holding the data effective for analyzing defect in a nonvolatile memory if a defect occurs by diagnosing the state of various devices related to the support of a steering and of easily controlling the memory. SOLUTION: When a diagnosing means determines that a defect has occurred, the defect information already stored in the nonvolatile memory (EEPROM) and newly generated defect information are compared with each other. When a newly occurred defect is a defect which is serious more than the already occurred one, the defect data on the newly occurred defect is overwritten and stored in the nonvolatile memory. When the newly occurred defect is minor, the overwriting is prohibited. COPYRIGHT: (C)2009,JPO&INPIT