曲轴位置传感器也称曲轴转角传感器，是计算机控制的点火系统中最重要的传感器，其作用是检测上止点信号、曲轴转角信号和发动机转速信号，并将其输入计算机，从而使计算机能按气缸的点火顺序发出最佳点火时刻指令。曲轴位置传感器有三种型式：电磁脉冲式曲轴位置传感器、霍尔效应式曲轴位置传感器、光电效应式曲轴位置传感器。曲轴位置传感器型式不同，其控制方式和控制精度也不同。曲轴位置传感器一般安装于曲轴皮带轮或链轮侧面，有的安装于凸轮轴前端，也有的安装于分电器。
Crankshaft position sensor, also known as crankshaft angle sensor, is the most important sensor in the computer-controlled ignition system. Its function is to detect the top dead center signal, crankshaft angle signal and engine speed signal, and input them into the computer, so that the computer can send out the best ignition time command according to the ignition sequence of the cylinder. There are three types of crankshaft position sensor: electromagnetic pulse crankshaft position sensor, Hall effect crankshaft position sensor and photoelectric effect crankshaft position sensor. Different types of crankshaft position sensors have different control modes and control accuracy. The crankshaft position sensor is generally installed on the side of crankshaft pulley or sprocket, some are installed in the front of camshaft, and some are installed in distributor.