What information does the manifold absolute pressure (MAP) sensor provide?

The manifold absolute pressure (MAP) sensor provides essential information about the absolute pressure of the intake air within the engine's manifold. This measurement is crucial for several reasons. First, it helps the engine control unit (ECU) determine the density of the intake air, which is influenced by the altitude and temperature. By knowing the absolute pressure, the ECU can accurately calculate the necessary fuel delivery to maintain the proper air-fuel mixture for efficient combustion.

In addition, the MAP sensor plays a vital role in the engine's performance by assisting in controlling various operations, such as ignition timing and fuel injection timing. This ensures optimal engine performance and emissions control under different operating conditions.

The other options do not describe the function of the MAP sensor accurately. The air-fuel ratio is determined by a combination of the MAP reading and other inputs, not solely by the MAP sensor. The temperature of the intake air is measured by a different sensor, typically the intake air temperature (IAT) sensor. Finally, the RPM of the engine is usually monitored by a separate sensor that detects the crankshaft or camshaft position.