- Transmission revs higher before it changes gears
- The car's transmission engages into overdrive late and sometimes will never go into that top gear
- Brakes are sometimes harder than normal when coasting
- Speedometer behaves erratically or sometimes does not work at all
- The check engine light comes on intermittently and sporadically when accelerating
- The overdrive on/off light blinks on and on for no apparent reason
What an Engine Speed Sensor Does.
How the Engine Speed Sensor WorksBeing attached to the crankshaft of the vehicle's engine, the engine speed sensor is meant to assess the speed at which the crankshaft spins. The device is basically a metal disk that has a serrated (toothed) circumference. In addition, there's a stationary device containing a magnetic coil, which acts as a standard for the measurement. When the crankshaft spins, induction current is set up around the magnetic coil. The serrated edge of the crankshaft obstructs the produced magnetic field and this is recorded. This is what gives a measurement of the amount of current produced, which is outputted as the speed of the vehicle's engine.
The engine speed sensor becomes an important device because it provides a real value for the engine's speed. Since every car has its own specific speed limit, this device is put into use when checking the overall performance of the car.
Problems with an Engine Speed SensorIf your vehicle has a faulty engine speed sensor, you will generally experience a problem with the air to fuel ratio and close associations with the coolant sensor. If you are having trouble with cruise control and speedometer issues, this will be attributed to the vehicle speed sensor.