Which component typically changes engine speed data?

The crankshaft sensor is primarily responsible for monitoring the position and rotational speed of the crankshaft. This information is crucial for the engine control unit (ECU) as it uses the crankshaft speed data to manage various aspects of engine operation, including fuel injection timing and ignition timing. By providing real-time data about how fast the crankshaft is rotating, the crankshaft sensor allows the ECU to adjust engine parameters to maintain optimal performance and efficiency.

In the context of the other options, while the throttle position sensor measures how open the throttle plate is and can indirectly influence engine speed through airflow, it's the crankshaft sensor that gives direct feedback on the actual speed of the engine. The mass airflow sensor measures the amount of air entering the engine, which is important for fuel mixture calculations but does not directly measure engine speed. The camshaft sensor tracks the position of the camshaft, which is critical for timing and valve operation but not for providing engine speed data directly. Therefore, the crankshaft sensor is the key component in changing and reporting engine speed data.