The crankshaft position sensor is usually located on the cylinder head of a vehicle. At the back of the engine, near the intake camshaft, there is a piece jutting out on the rear corner, which is the sensor. In older cars, the sensor may be inside the distributor cap.
Depending on the car model, the sensor can also be positioned on the front of the engine block near the water pump, on the flywheel, or on the main crank pulley. The sensor could be closer to the front bumper or next to the fender. The best move is to consult the owner's manual before looking.
If the sensor is in the distributor cap, and it's faulty, the cap must be replaced. Before doing so, it is important to write down where each cylinder wire goes. On a six-cylinder engine, the pattern is usually 1, 4, 2, 6, 3 and 5. This is the order in which the cylinders fire. It is best to mark the first terminal, then remove the cap. The crankshaft needs to be aligned and marked, as does the rotor, before the new cap is installed.
Signs that there is a defective crank sensor include problems starting the vehicle, engine shutting off for no reason, and misfiring. The Check Engine light may also go on.