Abstract: An electronic control device includes a nonvolatile memory having allocated two storage areas that are exclusively switchable between an active state and an inactive state, the storage area in the active state being used to store a control program to be executed, and the storage area in the inactive state being used as a reserved area for updating the control program. In the electronic control device, when the control program is not updated, arbitrary data is written in the storage area in the inactive state.

Abstract: An electronic control device includes: a microcomputer; a wake-up circuit; and a relay switch self-retaining a power relay, and the wake-up circuit operates the relay switch in response to a wake-up signal from an OTA electronic control device, and starts power supply to the microcomputer to cause starting-up. During shutdown processing for the microcomputer, the microcomputer outputs a stop command to the relay switch before outputting a stop command to the wake-up circuit, whereby an output terminal (INH terminal) of the wake-up circuit is diagnosed for fixation based on an output signal from the wake-up circuit.

Abstract: An electronic control device includes a nonvolatile memory having allocated two storage areas that are exclusively switchable between an active state and an inactive state, the storage area in the active state being used to store a control program to be executed, and the storage area in the inactive state being used as a reserved area for updating the control program. In the electronic control device, when the control program is not updated, arbitrary data is written in the storage area in the inactive state.