What kinds of throttle position sensors are there? What are their characteristics?

20 16 Toyota Camry Hybrid Vehicle (engine model 6AR-FSE) adopts a non-contact dual Hall element throttle position sensor, which is mainly composed of Hall element and magnet, in which the magnet is installed on the throttle shaft and can rotate around the Hall element.

The control circuit and signal output characteristics of Hall throttle position sensor are shown in the above figure. When the throttle opening changes, the magnet rotates with it, thus changing the relative position with the Hall element, and the Hall IC is surrounded by the yoke. Hall IC converts the change of magnetic flux into electrical signal, which is output to ECM in the form of throttle position signal.

2. Sliding resistance throttle position sensor

Sliding resistance throttle position sensor, also known as linear output throttle position sensor, variable resistance throttle position sensor and potentiometer throttle position sensor. At present, the dual variable resistance throttle position sensor is widely used in automobiles.

The sliding resistance throttle position sensor is a three-wire sensor, in which two pins are located at both ends of the resistor, which are used as the power supply terminal and the grounding terminal respectively, providing 5V voltage from the engine ECU, and the third pin is connected to the sliding contact.

The throttle shaft is connected with the contact (or contact). When the throttle rotates, the sliding contact can move on the resistor, causing the change of the potential of the sliding contact. Throttle position signal is converted into voltage value through the change of resistance.

Because this voltage changes linearly, it is also called linear output throttle position sensor. According to this linear voltage value, ECU can sense the throttle opening and make ECU correct the fuel injection quantity.

Extended data

The main function is to detect whether the engine is in idle or load condition, acceleration or deceleration condition. It is essentially a variable resistor and several switches, which are installed on the throttle body. Its shape and internal structure are shown in the following figure.

The rotating shaft of the resistor is connected with the throttle valve, and it has two contacts: a fully open contact and an idle contact. When the throttle is in the idle position, the idle contact is closed and the idle state signal is output to the computer.

When the throttle valve is in other positions, the idle contact is opened, and voltage signals with different angles relative to the throttle valve are output, and the computer identifies the engine load according to the signal voltage value; According to the change rate of signal voltage in a certain period of time, whether it is an acceleration state or a deceleration state is identified. According to these working conditions, the computer corrects the fuel injection quantity or controls the fuel cut-off.

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