A throttle position sensor (TPS) is a

sensor A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends ...

used to monitor the air intake of an engine. The sensor is usually located on the

butterfly Butterflies are insects in the macrolepidopteran clade Rhopalocera from the Order (biology), order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The ...

spindle/shaft, so that it can directly monitor the position of the throttle. More advanced forms of the sensor are also used. For example, an extra "closed throttle position sensor" (CTPS) may be employed to indicate that the throttle is completely closed. Some

engine control unit An engine control unit (ECU), also commonly called an engine control module (ECM), is a type of electronic control unit that controls a series of actuators on an internal combustion engine to ensure optimal engine performance. It does this by re ...

s (ECUs) also control the throttle position by

electronic throttle control Electronic throttle control (ETC) is an automobile technology which electronically "connects" the accelerator pedal to the throttle, replacing a mechanical linkage. A typical ETC system consists of three major components: (i) an accelerator ped ...

(ETC) or "

drive by wire Drive by wire, DbW, by-wire, steer-by-wire, fly-by-wire or x-by-wire technology in the automotive or aviation industry is the use of electrical or electro-mechanical systems for performing vehicle functions traditionally achieved by mechanical link ...

" systems, and if that is done, the position sensor is used in a

feedback loop Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled c ...

to enable that control. Related to the TPS are accelerator pedal sensors, which often include a

wide open throttle Wide open throttle or wide-open throttle (WOT), also called full throttle, is the fully opened state of a throttle on an engine (internal combustion engine or steam engine). The term also, by extension, usually refers to the maximum-speed state o ...

(WOT) sensor. The accelerator pedal sensors are used in

or "

" systems, and the most common use of a wide open throttle sensor is for the

kick-down An automatic transmission (sometimes abbreviated to auto or AT) is a multi-speed transmission used in internal combustion engine-based motor vehicles that does not require any input from the driver to change forward gears under normal driving co ...

function on

automatic transmission An automatic transmission (sometimes abbreviated to auto or AT) is a multi-speed transmission used in internal combustion engine-based motor vehicles that does not require any input from the driver to change forward gears under normal driving c ...

s. Modern day sensors are non contact type. These modern non contact TPS include

Hall effect sensors A Hall effect sensor (or simply Hall sensor) is a type of sensor which detects the presence and magnitude of a magnetic field using the Hall effect. The output voltage of a Hall sensor is directly proportional to the strength of the field. I ...

inductive sensor An inductive sensor is a device that uses the principle of electromagnetic induction to detect or measure objects. An inductor develops a magnetic field when a current flows through it; alternatively, a current will flow through a circuit contain ...

s, magnetoresistive and others. In the

potentiometric A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat. The measuring instrum ...

type sensors, a multi-finger metal brush/rake is in contact with a resistive strip,Garrick, R.D., Sensitivity of Contact Electronic Throttle Control Sensor to Control System Variation, Society of Automotive Engineers (SAE) Technical Paper, 2006-01-0763, April 2006. while the butterfly valve is turned from the lower mechanical stop (minimum air position) to WOT, there is a change in the resistance and this change in resistance is given as the input to the ECU. Non contact type TPS work on the principle of

Hall effect The Hall effect is the production of a voltage difference (the Hall voltage) across an electrical conductor that is transverse to an electric current in the conductor and to an applied magnetic field perpendicular to the current. It was disco ...

or inductive sensors, or magnetoresistive technologies, wherein generally the magnet or inductive loop is the dynamic part which is mounted on the butterfly valve throttle spindle/shaft gear and the sensor & signal processing circuit board is mounted within the ETC gear box cover and is stationary. When the magnet/inductive loop mounted on the spindle which is rotated from the lower mechanical stop to WOT, there is a change in the magnetic field for the sensor. The change in the magnetic field is sensed by the sensor and the voltage generated is given as the input to the ECU. Normally a two pole rare-earth magnet is used for the TPS due to their high

Curie temperature In physics and materials science, the Curie temperature (''T''C), or Curie point, is the temperature above which certain materials lose their permanent magnetic properties, which can (in most cases) be replaced by induced magnetism. The Cur ...

s required in the under-hood vehicle environment. The magnet may be of diametrical type, ring type, rectangular or segment type. The magnet is defined to have a certain magnetic field that does not vary significantly with time or temperature.

Notes

{{DEFAULTSORT:Throttle Position Sensor Engine sensors

See also

Notes