Celica GT Ltd Ed Convertible L4-2164cc 2.2L DOHC MFI (1997)
Manifold Absolute Pressure (MAP) Sensor: Description and Operation
CIRCUIT DESCRIPTION
By a built-in sensor unit, the manifold absolute pressure sensor detects the intake manifold pressure as a voltage. The ECM then determines the
basic injection duration and basic injection advance angle based on this voltage. Since the manifold absolute pressure sensor does not use the
atmospheric pressure as a criterion, but senses the absolute pressure inside the intake manifold (the pressure in proportion to the present absolute
vacuum 0), it is not influenced by fluctuations in the atmospheric pressure due to high altitude and other factors. This permits it to control the
air-fuel ratio at the proper lever under all conditions.
