Turbocharger Bypass Control System

Turbocharger Bypass Control System

This system improves the boost response of acceleration immediately after deceleration. This system also protects the turbocharger from the negative effects of compressor surge during high boost. The descriptions A and B are the two conditions of the turbocharger bypass control solenoid valve on and off. Condition A (on) and condition B (off).

Condition A (Solenoid Valve ON):

When the vehicle is in cruise or accelerating, the PCM turns on the turbocharger bypass control solenoid valve, and opens the passage between the charge air cooler and the turbocharger bypass control valve and closes the passage between the intake manifold and the turbocharger bypass control valve. The boost pressure from the charge air cooler pushes the turbocharger bypass control valve, and closes the passage between the charge air cooler and the intake air duct (turbocharger inlet pipe). By doing this, all compressed air is routed to the intake manifold.






Condition B (Solenoid Valve OFF):

During the deceleration with the throttle valve closed, the PCM turns off the turbocharger bypass control solenoid valve and opens the passage between the intake manifold and the turbocharger bypass control valve and closes the passage between the charge air cooler and the turbocharger bypass control valve. The vacuum pressure from the intake manifold pulls the turbocharger bypass control valve and opens the passage between the charge air cooler and the intake air duct (turbocharger inlet pipe). By doing this, the compressed air flows from the charge air cooler to the intake air duct (turbocharger inlet pipe) to keep the turbine spinning. This improves the acceleration response of the turbocharger after deceleration.