Vacuum Sensor (1.6L & 2.2L)
WARNING: This page is about a different car, the 1993 Toyota Celica. However, it is still accessible from the selected car via links, so may be relevant.
Vacuum sensor may also be referred to as Manifold Absolute Pressure (MAP) sensor. Vacuum sensor monitors intake manifold intake air volume and delivers an input signal to Engine Control Module (ECM). The ECM uses input signal for controlling fuel injection system and ignition timing (spark advance).