Crankshaft sensors -- used on fuel injected vehicles -- tell the computer, via a voltage signal, the location of the crankshaft at the No. 1 cylinder, as well as the engine rpm. The computer uses the signal to adjust the ignition timing and injectors. If the crankshaft sensor malfunctions, the vehicle will not start, because the engine loses its timing signal. On some vehicles, the crankshaft sensor works alone, but more commonly, it works in conjunction with a camshaft sensor.
Locate the crankshaft position sensor on your particular vehicle. The most common places for the sensor is behind the crankshaft pulley or under the timing cover.
Remove the specific components on your vehicle to gain access to the sensor.
Unplug the sensor's electrical wiring harness connector by pulling the tangs on each side of the connector out, then pulling the connector off the sensor.
Remove the retaining bolt or bolts holding the sensor on the block, then left the sensor off the engine.
Install the new sensor and tighten the retaining bolt or bolts firmly. Do not over tighten the bolts, as you could damage the sensor. Plug in the wiring harness connector, ensuring that the tangs snap over the connector. Reinstall the rest of the parts in reverse order of removal.