Your vehicle's crankshaft sensor can be, well, cranky. But it's also a key part you can't do without. So what makes one fail? And how do you know if it's bad?

Related: The crankshaft position sensor, typically mounted near or on the crankshaft, tells the engine computer how fast the engine is running.

I’ve been driving all night, my hands wet on the wheel...but I have no idea how fast I’m going. Check out our advice on how to test a transmission speed sensor.