Accord L4-2.2L SOHC VTEC (1994)
Manifold Pressure/Vacuum Sensor: Description and Operation
MAP Sensor Cutaway/Voltage Output Characteristics
PURPOSE
The Engine Control Module (ECM) uses the Manifold Absolute Pressure sensor signal to sense engine load so that ignition timing and fuel
delivery can be adjusted to maintain consistent engine performance.
CONSTRUCTION
The sensor consists of a silicon diaphragm and some support circuitry.
OPERATION
The ECM supplies a 5 volt signal and a ground to the sensor. A vacuum line supplies intake manifold vacuum to a small cavity under the silicon
diaphragm which causes the diaphragm to flex. The flexing of the silicon generates a small voltage which is amplified by the support circuitry and
used to modify the fixed 5 volt signal supplied by the ECM. The modified signal is then returned to ECM.
