Manifold Pressure/Vacuum Sensor: Description and Operation

Pressure Sensor:

PURPOSE
Provides the ECM with intake air volume measurement.

LOCATION
On the firewall.

PS Output Voltage Characteristics:

OPERATION AND OPERATION
This sensor senses pressure change in the intake manifold and converts it into voltage change. It consists of a semi-conductor type pressure converting element which converts a pressure change into an electrical change and an electronic circuit which amplifies and corrects the electric change. The ECM sends a 5-volt reference voltage to the pressure sensor. As the manifold pressure changes, the electrical resistance of the sensor also changes. By monitoring the sensor output voltage, ECM knows the manifold pressure (intake air volume). The ECM uses the signal as one of the signals to control fuel injector duration, ISC valve operation, EGR VSV operation, shift-up indicator lamp and ignition timing.