Symptoms

- Engine Light ON (or Service Engine Soon Warning Light) - Engine rough idle - Engine hesitation

Possible Causes

- Manifold Absolute Pressure harness is open or shorted - Manifold Absolute Pressure sensor poor electrical circuit connector - Faulty Manifold Absolute Pressure sensor - Faulty Powertrain Control Module (PCM)

When Detected

Manifold Absolute Pressure (MAP) sensor input voltage is above the minimum acceptable value

Description

The Manifold Absolute Pressure (MAP) sensor provides instantaneous manifold pressure information to the engine'sPowertrain Control Module (PCM). The data is used to calculate air density and determine the engine's air mass flow rate, which in turn determines the required fuel metering for optimum combustion. A fuel-injected engine may alternately use a Mass Air Flow (MAF) sensor to detect the intake airflow. A typical configuration employs one or the other, but seldom both.