Intake Manifold Absolute Pressure Sensor (Map Sensor)

Located on intake manifold housing. Also use qty (1) screw 99991924101

The Manifold Absolute Pressure (MAP) sensor is essentially an electronic version of the vacuum advanced diaphragm used in mechanical distributors. The MAP sensor measures the difference (or absolute pressure differential) between the air inside the manifold and the ambient air pressure. The sensor sends a voltage or frequency signal representing engine (intake) vacuum to the Engine Control Module (ECM). The ECM adjusts air/fuel ratio and ignition timing according to changes in engine vacuum.

A faulty MAP sensor will affect the ability of the ECM to adjust air/fuel ratio and ignition timing due to inaccurate calculation the engine load. This can result in an excessively rich or lean air-fuel mixture. Symptoms of a faulty MAP sensor can include:

• Malfunction Indicator Light (MIL) illumination or Check Engine Light (CEL)
• Lean or rich air-fuel mixture
• Failed emissions test
• Poor fuel economy