Idle Speed: Notes

Engine idle speed is controlled by ECU based on engine operating conditions and component/model application. ECU senses engine operating conditions and determines best idle speed. Basic idle speed is adjusted by changing amount of air by-passing throttle plate via Auxiliary Air Control (AAC) Valve.

Fast idle required for cold starts is accomplished through use of an ECU-controlled Fast Idle Control Device (FICD) and air regulator (G20 and M30) or thermowax pellet fast idle cam (Q45).