A MAP (Manifold Absolute Pressure) sensor measures the air pressure inside an engine's intake manifold and sends this information to the engine's electronic control unit (ECU or ECM). This data is crucial for calculating air density and determining the engine's air mass flow rate, which the ECU uses to adjust fuel delivery and ignition timing for optimal combustion and engine performance
. Specifically, the MAP sensor helps the ECU:
- Calculate the correct air-fuel ratio by measuring intake manifold pressure and combining it with data from other sensors like intake air temperature and engine speed
- Adjust ignition timing based on engine load conditions
- Monitor throttle and turbocharger performance and detect leaks in the intake manifold
- Act as a barometric pressure sensor when the engine is off, providing ambient pressure data to help with air density calculations
In turbocharged engines, the MAP sensor also monitors boost pressure, often working alongside a mass airflow (MAF) sensor to optimize engine performance
. In summary, the MAP sensor is a vital component in fuel-injected engines that ensures efficient fuel delivery, helps maintain proper engine performance, and supports emission control by accurately measuring intake manifold pressure
