Circuit Description: Notes

The throttle body assembly contains an idle speed control (ISC) motor that is used to control the engine speed at idle. The engine control module (ECM) commands the ISC motor to adjust the throttle angle for idle speed control. An idle switch is also integrated into the throttle body assembly. The idle switch position is dependent upon the position of the throttle. The ECM receives an ON signal from the idle switch when the throttle is at idle and receives an OFF signal from the switch when the throttle is open.

The following table illustrates the correlation between the idle switch and the throttle position: