To provide vehicle electronic control devices for preventing unauthorized deletion of vehicle abnormality information stored in a nonvolatile memory even if software is rewritten.

Various vehicle electronic control devices, for example, an engine control device, a brake control device and a transmission control device are mounted on a vehicle and various pieces of vehicle abnormality information are stored in a nonvolatile memory in each vehicle electronic control device. On rewriting software, a checker reads the vehicle abnormality information from a vehicle electronic control device, the read vehicle abnormality information is transmitted to the vehicle electronic control device, the vehicle electronic control device updates the software only in the case that the abnormality information received from the checker coincides the abnormality information stored in the nonvolatile memory and then the vehicle abnormality information is written to the nonvolatile memory.