Air Conditioning Switch: Description and Operation

Throttle Opening System (Throttle Opener Solenoid For A/C):

When the A/C relay is engaged, an ``A/C On'' signal is sent to the ECU. Based on this and other load indicating signals, the ECU controls the ground to the throttle opener system. When the ECU provides a ground it allows operation of the throttle openers for either or both of the idle speed devices. In the case of the A/C, when the engine speed is below the set speed (1,200 RPM), the ECU provides a ground. When the air conditioner relay is turned on the throttle opener control solenoid valve is energized to introduce intake manifold vacuum to the throttle opener. The throttle valve opens slightly preventing engine speed drop caused by air conditioner load.