Throttle Full Close Switch: Description and Operation

Fig. 8 Idle switch:

The idle switch Fig. 8,detects when the throttle valve is completely closed and supplies the electronic control assembly with a signal. The signal from the idle switch affects, air/fuel ratio, injector timing, idle speed, EGR flow and ignition timing (turbocharged engine). The idle switch is threaded into the throttle body where it comes into contact with the throttle linkage.