Barometric Pressure Switch: Description and Operation

Fig. 2 Barometric pressure switch. 1.3L FBC models:

The barometric pressure (BP) switch, Fig. 2, is turned on when a decrease in atmospheric pressure occurs. The ECA will then compensate for the altitude the vehicle is operating at. The ECA uses this information to control ignition timing, air/fuel ratio, EGR flow and the shift indicator light. The BP switch is located under the instrument panel at the lefthand of the steering column assembly.