Variable Induction System: Description and Operation

Block Diagram:

Operation
- The PCM turns the variable tumble control solenoid valve ON to close the crescent shaped shutter valve in the intake manifold when all of the following conditions have been met:
i. ECT is below 65 °C {149 °F}.
ii. Engine speed is below 3,000 rpm.
iii. Throttle opening angle is below preset value.
iv. ECT sensor and TP sensor are not malfunctioning.

- The PCM turns the VTCS solenoid valve OFF to maintain startability and stability during engine cranking and for 0.15 second after engine is started.