คำตอบที่ 1
อิอิ ....ลองใช้อากูแปลดูนะคุณครู...by the book
senses Manifold Absolute Pressure (MAP). The vehicle computer calculates how much fuel to deliver to the engine based on the amount of load being applied to the engine. The computer uses manifold pressure, barometric pressure, engine RPM and throttle angle to determine engine load. Fuel ratio and spark timing are then fine tuned by the computer using additional sensors, this also helps to control fuel economy and emissions. Some vehicles use a Mass Air Flow sensor to measure the amount of air entering the engine, this also is used to determine engine load, in some cases there may be a MAP sensor and a MAF sensor. In that configuration the MAP is used for Barometric pressure and is a back up should the MAF fail, the computer will illuminate the Service Engine Soon lamp and use a calculated air fuel mixture to allow the driver to get to a repair shop without damaging the catalytic converter.
The MAP sensor doubles as a barometric sensor. The computer will read barometric pressure when the key is turned on prior to engine cranking and then every time the computer senses wide open throttle it will check Baro pressure again.
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