Manifold Pressure/Vacuum Sensor: Description and Operation

PURPOSE
The Digifant Engine Control Module (ECM) uses this signal along with the engine speed signal to help determine the ignition timing and injector duration.

Manifold Pressure Sensor:

CONSTRUCTION AND OPERATION
The sensor consists of a crystal ship and two semiconductors. The crystal is hollow inside and, when it is mounted to its base plate, air is trapped between the base plate for the crystal and the chip.

Since the chip is hollow, the top of the chip will flex when pressure is applied. Two semiconductors are attached to the top of the crystal and sense the flexing of the chip.

The flexing of the chip causes the semiconductors to alter their shape. This changes the resistance values of the semiconductors. This change in resistance is used by the Digifant control module to determine engine load.

LOCATION
The Manifold Absolute Pressure (MAP) sensor is located inside the Digifant ECM.