Throttle Body: Description and Operation

Air flow to the engine is controlled by the throttle body through a single butterfly-type valve. Throttle position is controlled by a cable/cam throttle linkage. The throttle body has a single bore with an air bypass channel around the throttle plate. The bypass channel controls both cold and warm engine idle air flow which is regulated by an air bypass valve assembly mounted on the throttle body. The air bypass valve is controlled by the ECU and incorporates a linear actuator which positions a variable area metering valve.