•  When all of the following conditions are met, the PCM energizes the coil of variable swirl solenoid valve. As a result, negative pressure is introduced to the diaphragm chamber of the variable swirl shutter valve actuator, pulling the actuator rod and closing the variable swirl shutter valve.

•  When a DTC for the engine coolant temperature sensor or MAF sensor has been stored, the variable swirl control is inhibited and the variable swirl shutter valve is constantly open.