RPM rev counter sensors play an integral role in helping drivers to monitor the overall speed and function of their vehicle. This part works with other components like the tachometer to help prevent drivers from going so fast that they are pushing their vehicle’s engine into the red zone. This zone will vary depending on the vehicle. Driving in the red can cause damage to the vehicle in the form of premature wear and tear, engine overheating and the engine not getting properly lubricated. It senses crankshaft rotations to help show the RPMs that the vehicle is operating at. If the RPMs of a vehicle do not seem accurate, it might be time to start looking at RPM rev counter sensors for a replacement.