Manifold Pressure/Vacuum Sensor: Description and Operation

DESCRIPTION






NOTE: This sensor monitors both Inlet Air Temperature (IAT) and Manifold Air Pressure (MAP).

The sensor is installed in the intake manifold with the sensor element extending into the air stream.

The Intake Air Temperature (IAT) portion of the sensor is a two-wire Negative Thermal Coefficient (NTC) sensor. Meaning, as inlet air temperatures increase, resistance (voltage) in the sensor decreases. As temperature decreases, resistance (voltage) in the sensor increases.

The Manifold Air Pressure (MAP) portion of the sensor provides instantaneous manifold pressure information to the Powertrain Control Module (PCM). The data is used to calculate air density and determine the engines air mass flow rate, which in turn determines the required fuel metering for optimum combustion.