Idle Control System: Notes

Idle speed is controlled by ECM through IAC valve. ECM controls idle speed components based upon signals received from various input devices. If idle speed components test correctly but idle speed is not being regulated properly, check input signals to ECM. See IDLE SPEED SYSTEM INPUT SIGNALS table.

Fast idle is controlled by fast idle cam. For fast idle cam adjustment procedure, see IDLE SPEED & MIXTURE in ADJUSTMENTS article.