The engine has two temperature sensors, an Engine Coolant Temperature Sensor(ECTS) and an Intake Air Temperature Sensor(IATS), to detect the temperature while the engine is in operation. A thermistor, whose resistance value varies according to the temperature, is built into each sensor. When the temperature is low, the resistance of the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are transmitted to the ECM/PCM as voltage changes. Based on these temperature signals output from the sensors, the ECM/PCM determines the fuel injection time and the ignition timing to control the engine.