Idle Speed Control (ISC) Solenoid Operation

Throttle Body Component Location:

The Bypass Air Control is a supervising component of the idle speed control system. The BAC regulates the amount of intake air allowed to bypass the throttle valve under a full range of operating conditions. For cold engine operation, the BAC valve operation is controlled by the use of thermo wax element that contracts and expands from the engine coolant surrounding the element. After engine warm-up, the Electronic Control Assembly (ECA) controls the Idle Speed Control (ISC) solenoid valve to maintain good idle quality smoothness under various conditions.