The engine's crankshaft position sensor plays a vital role in ensuring your vehicle is performing at its best. Here are five warning signs that it is bad.

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?

The crankshaft position sensor is the most important of all engine management sensors, and the engine will absolutely not run without it.

First off, the reluctor has to be properly indexed to the crank or your ECU will get inaccurate crank position info, which can cause a host of problems.