FUNCTION
The Variable Valve Timing-intelligent (VVT-i) system is designed to control the intake camshafts within a range of 50° (of crankshaft angle) to provide valve timing that is optimally suited to the engine operating conditions. This improves torque in all the speed ranges as well as increasing fuel economy and reducing exhaust emissions.
| *1 | Cam Position Sensor (Bank 1) | *2 | Cam Timing Oil Control Valve Assembly RH (Bank 1) |
| *3 | Cam Position Sensor (Bank 2) | *4 | Crank Position Sensor |
| *5 | Cam Timing Oil Control Valve Assembly LH (Bank 2) | *6 | Engine Coolant Temperature Sensor |
| *7 | ECM | *8 | Accelerator Pedal Position Sensor |
| *9 | Throttle Position Sensor | - | - |
The VVT-i system delivers excellent benefits in the different operating conditions as follows:
During Idling
| Objective | Effect |
|---|---|
| Eliminating overlap to reduce blowback to the intake side. |
|
At Light Load
| Objective | Effect |
|---|---|
| Decreasing overlap to reduce blowback to the intake side. | Ensured engine stability |
At Medium Load
| Objective | Effect |
|---|---|
| Increasing overlap to increase internal EGR to reduce pumping loss. |
|
In Low to Medium Speed Range with Heavy Load
| Objective | Effect |
|---|---|
| Advancing the intake valve close timing to improve volumetric efficiency. | Improved torque in low to medium speed range |
In High Speed Range with Heavy Load
| Objective | Effect |
|---|---|
| Retarding the intake valve close timing to improve volumetric efficiency. | Improved output |
At Low Temperatures
| Objective | Effect |
|---|---|
| Eliminating overlap to prevent blowback to the intake side leads to the lean burning condition, and stabilize the idling speed at fast idle. |
|
Starting and Stopping Engine
| Objective | Effect |
|---|---|
| Eliminating overlap to minimize blowback to the intake side. | Improved startability |