Idle Speed: Description and Operation

PURPOSE
To improve idle smoothness.

OPERATION
The idle speed control (ISC) system controls the intake air amount by regulating amount of the bypass air that passes through the throttle valve.

CONSTRUCTION
This system consists of the air valve that functions only when the engine is cold, the idle air control valve that works throughout the entire engine speed range, the powertrain control module engine (PCME) and input devices. Both the air valve and the idle air control valve are integral components of the by-pass air control (BAC) valve assembly.