A throttle position sensor is a device that can detect a difference in throttle position. The Engine Control Unit (ECU) uses throttle position sensors in internal combustion engines to gauge the throttle’s position as well as the rate of change in the throttle’s position in order to relay this information to other devices in the engine. In fact, virtually all internal combustion engines’ ignition timing and fuel injection rely on a throttle position sensor.
Although throttle position sensors are almost exclusively found in internal combustion engines, they can perform several different tasks. For example, some ECUs can electronically control the throttle position and use the throttle position sensor as a feedback loop to do so. These types of ECUs are typically found in drive-by-wire systems. Throttle position sensors are also found in other devices, such as remote control vehicles and any other device that uses throttle.
While there are many different types of throttle sensors, there are only two types of throttle position sensors: switch and potentiometer. In a switch-based throttle position sensor, the switch is always on and provides a continuous current of electricity while the throttle is in use. When the throttle is not in use, the switch is off and does not allow electricity to flow. A potentiometer, however, sends a very low voltage to the ECU when the ignition is on but the throttle is off. It then increases the voltage as the throttle is increased, usually reaching a peak of 5 Volts when the throttle reaches its maximum.
Symptoms of a Bad Throttle Position Sensor
Because throttle position sensors contain both electrical and mechanical parts, they are susceptible to damage from long term use just like any other device. When a throttle position sensor is malfunctioning, the car may jerk while being driven, the engine may stall spontaneously, the vehicle might hesitate when trying to accelerate, or the car may accelerate too much. Likewise, it may be difficult to change gears, the car may use a lot more fuel than usual, or the Engine Malfunction Indicator light may come on. The throttle position sensor’s false readings cause all these things, but replacing it can remedy this problem.
Where to Find a Throttle Position Sensor
Throttle position sensors can be found virtually anywhere, especially in automotive supply stores or the automotive section of any supermarket such as Walmart. They can also be purchased directly from automotive repair shops or the auto shop can purchase it from a third party. Auto insurance companies often know where to find good deals on throttle position sensors, although additional research comparing rates and reputation can be done online.