Map Sensor: Description
WARNING: This page is about a different car, the 2005 Dodge SX, 2005 Dodge SRT-4, and 2005 Dodge Neon. However, it is still accessible from the selected car via links, so may be relevant.
The MAP sensor mounts to the intake manifold. See Fig 1 .
The MAP sensor signal is provided from a single piezoresistive element located in the center of a diaphragm. The element and diaphragm are both made of silicone. As the pressures changes the diaphragm moves causing the element to deflect which stresses the silicone. When silicone is exposed to stress its resistance changes. As manifold vacuum increases, the MAP sensor input voltage decreases proportionally. The sensor also contains electronics that condition the signal and provide temperature compensation.