CAR CONTROL DEVICE

PURPOSE:To prevent any mis-writing caused by the instant drop of a battery voltage and a sudden noise and the like occurred during EEPROM writing by providing a EEPROM in a serial data transmission type and a battery backup RAM, in a car control device providing CPU. CONSTITUTION:During engine running, the most favorable fuel injection amount and an ignition timing and the like are calculated based on an engine running status and a control parameter is studyed by an aging change, a solid difference and the like so as to memorize to EEPROM 1 in CPU2. Meantime, when the control parameter is written in EEPROM 1, a written data and address are firstly stored in a battery backup RAM 4 temporarily and a written flag is set. Then, the data is written in EEPROM 1 and also whether its written in operation is finished or not is judged and after finish judging, the data is read out from the written same address. The content of EEPROM 1 is compared with the content of the battery backup RAM 4 and its process is finished in the case of the same each other.