October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Vacuum Switch

The vacuum switch is a contact type that is operated by intake manifold vacuum. When throttle valve closes, intake manifold vacuum closes switch. At this point, voltage on ECU side is grounded and the ECU senses throttle valve opening is near idle position. This information is used for controlling air/fuel mixture at idle with secondary air control.