A window regulator is used in General Motors vehicles to raise and lower the glass pane inside a door. This window regulator is actually a mechanical lever that is activated by means of a hand crank inside the vehicle, which can be damaged due to some reasons and hence it should be replaced.

GMC Sierra has a crank sensor (popularly called as crankshaft position sensor or CKP) which is a small magnetic sensor that usually measures the rotation of the crankshaft. The crank sensor first measures the engine RPMs and afterward passes on that information to the engine control computer.