What does the throttle position sensor (TPS) indicate?

The throttle position sensor (TPS) is a critical component in modern engine management systems. Its primary function is to measure the position of the throttle valve, which is part of the air intake system. This measurement is essential because it helps the engine control unit (ECU) determine how much air is entering the engine. By knowing the throttle valve position, the ECU can adjust the fuel mixture and spark timing accordingly to optimize engine performance, fuel efficiency, and emissions.

When the throttle is opened, more air enters the engine, prompting the ECU to increase fuel delivery to maintain a proper air-fuel ratio. Similarly, if the throttle is closed, the ECU reduces fuel delivery. This feedback loop is crucial for achieving smooth engine operation and responding appropriately to the driver's inputs, such as accelerating or decelerating. Thus, the throttle position sensor plays a vital role in the overall performance and efficiency of the engine, which is why this option correctly reflects its purpose.