Idle Speed/Throttle Actuator - Mechanical: Description and Operation

Bypass Air Valve:

Idle Speed Control Valve And Air Valve:

PURPOSE
Permits an additional amount of measured air to bypass the throttle valve for cold start fast idle.

LOCATION
Bottom of intake manifold dynamic chamber.

OPERATION
Temperature sensitive valve is open when cold and closed at engine operating temperature. As the valve is warmed by engine coolant, it closes and idle speed control is assumed by the ECU through signals to the idle speed control (ISC) valve.