The electronically controlled throttle is located upstream of the EGR valve in the intake manifold. It controls the throttle valve at an optimal angle to regulate the EGR gas and reduce noise and harmful exhaust gases.
• Signals from the engine ECU actuate the stepping motor, which regulates the throttle valve opening.
EGR Control
• To further increase the EGR volume when the EGR valve is fully open, the vacuum in the intake manifold can be increased by reducing the throttle valve opening, which restricts the flow of the intake air.
Noise and Exhaust Gas Reduction
• When the engine is being started, the throttle valve opens fully to reduce the emissions of white and black smoke.
• When the engine is being stopped, the throttle valve closes fully to reduce vibration and noise.
• During normal driving, the throttle valve opening is controlled in accordance with the engine conditions, coolant temperature, and atmospheric pressure.
