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

Vacuum switch is operated by intake manifold vacuum. When throttle valve closes, intake manifold vacuum closes switch. The voltage on ECU side is grounded and ECU senses throttle valve opening is near idle position. This information controls air/fuel mixture at idle with secondary air control.