摘要 |
A method for hydraulically filling a clutch without using a calibration routine. The clutch comprises a spring and a clutch cavity, and the spring and the clutch cavity are positioned inside of the clutch. A valve is associated with the clutch and is configured for allowing a fluid to flow to and from the clutch cavity. The method comprises the step of sending a wakeup current to a valve. The wakeup current is sent to the valve for allowing the fluid to substantially fill the clutch cavity. Still further, the method comprises the step of determining whether the spring is compressed and, also, determining whether a speed ratio of the powertrain is unknown. Further yet, the method comprises the step of sending a ramped hold current that rises relatively gradually to the valve if the spring is compressed and if the speed ratio is unknown. |