Throttle position sensor function

The throttle position sensor is also called throttle opening sensor or throttle switch. Its 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 valve is in the idle position, the idle contact is closed and the idle working condition 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.

Extended data:

Throttle maintenance:

1, put the gas pedal

Engine oil will be heated and volatilized during use. The longer the use time, the higher the temperature and the stronger the volatilization. In addition, the compressed gas of the cylinder will squeeze into the crankcase through the gap of the piston ring, so there must be a channel for the gas to escape, otherwise the oil bottom will form positive pressure.

2, negative pressure suction

The reason why the crankcase ventilation pipe is connected to the throttle valve is the requirement of environmental protection on the one hand, and the gas is pumped out of the crankcase by using the negative pressure of intake air on the other hand.

When the oily steam reaches the intake pipe and cools, the oil in it will condense on the intake and throttle valve, and then the carbon deposit in the steam will also be deposited on these parts. Because the air flow is the largest in the gap where the throttle valve is opened, the space is small and the gas temperature is low, this part is the easiest to condense.

3. Cleaning frequency

Therefore, how long the throttle will be dirty depends on the quality of the air filter, the brand and quality of the engine oil, the condition of the driving section, the temperature, the working temperature of the engine, driving habits and so on. Even for individuals, it is impossible to determine the time to clean the throttle with a fixed number of kilometers.

The interval between cleaning the throttle for the first time in new cars is the longest. In the future, due to the continuous condensation of oil and gas in the crankcase ventilation pipe and air inlet, the cleaning frequency will increase, and different weather conditions will also affect the dirty speed of the throttle.

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