What does MAP mean in cars?

[StCorey]

MAP in cars stands for Manifold Absolute Pressure, which is the intake pressure sensor. It connects to the intake manifold via a vacuum tube and senses the vacuum changes inside the intake manifold as the engine operates at different speeds and loads. The sensor then converts the changes in internal resistance into a voltage signal, which is used by the ECM (Engine Control Module) to adjust fuel injection and ignition timing. The ECM supplies a 5V voltage to the MAP sensor, and the signal terminal detects the voltage value. When the engine is idling, the voltage signal is approximately 1 to 1.5V, and when the throttle is fully open, the voltage signal is about 4.5V. The MAP sensor measures the absolute pressure in the intake manifold behind the throttle. Based on engine speed and load, it detects changes in the absolute pressure within the manifold and converts these into a voltage signal sent to the Engine Control Unit (ECU). The ECU uses this voltage signal to determine the basic fuel injection quantity.