The PCM controls the transmission in such a way as to reduce the engine speed to maintain its cooling capacity when the vehicle accelerates at wide open throttle. If you constantly drive at wide open throttle, the PCM modulates the hydraulic pressure on the pulley to increase the gear ratio, which in turn reduces the engine speed and maintains the designed cooling capacity. After driving the vehicle at a lower engine speed for some time, the PCM returns the pulley ratio to its original value.
The starting clutch is used to ensure smooth starting. It provides the same inertia as conventional automatic transmissions. Clutch operation and inertia in D, L and R positions are controlled by clutch hydraulic pressure, and clutch hydraulic pressure is electronically controlled by the PCM. In order for the start clutch to work properly, the PCM regulates the hydraulic pressure in the start clutch based on the vacuum value in the engine in the N position stored in the memory.
Starting clutch function
The starting clutch generates two types of inertia, weak and strong, under the following conditions:
- Low inertia conditions: Position D (including Sport mode), brake pedal depressed, vehicle stationary, throttle closed, engine coolant temperature above 75°C.
- Strong inertia conditions: Other conditions than the weak inertia conditions in position D.