When an alcohol mixed fuel is supplied to an internal combustion engine, the magnitude of the alcohol concentration is determined, and the magnitude of an operation state temperature is determined on the basis of the determination. The apparatus allows the multiple-ISA CPU to select a particular ISA decoding mode corresponding to a program instruction. The plug connector being arranged in a plug socket, the housing part being in two parts comprising a base part and an insert plate which is connected to the base part via a snap-action positive fit connection.