GF27.20-P-3002CWQ Torque Converter Lockup Clutch Control, Function

GF27.20-P-3002CWQ Torque Converter Lockup Clutch Control, Function
- TRANSMISSION 722.9 in MODEL 204.0 up to Model Year 8

The clutch pressure in the torque converter lockup clutch is drawn from the working pressure by means of the torque converter lockup clutch regulating valve. The position of the regulating valve is influenced by the torque converter lockup clutch control solenoid valve (Y3/8y8). The clutch pressure in the torque converter lockup clutch depends on the regulating valve position and thus on the geometry of the torque converter lockup clutch regulating valve. The torque converter lockup clutch has the following control states:
^ Open
^ Open-slipping
^ SLIPPING
^ Slipping-open

"Open" control state"

The regulating valve of the torque converter lockup clutch is located in the basic position. The working pressure acts on the converter regulating valve via a connecting line between the torque converter lockup clutch regulating valve and the converter regulating valve.

Lubrication pressure is applied to the converter as a result. The torque converter lockup clutch is in the unpressurized condition.

Control state "open-slipping"

The torque converter lockup clutch regulating valve is no longer in the basic position and as a result interrupts the connection between the torque converter lockup clutch regulating valve and the converter regulating valve. The torque converter lockup clutch is filled.

Control state "slipping"

The required slip (specified slip) is stored in the fully integrated transmission control control unit (Y3/8n4). The fully integrated transmission control control unit (Y3/8n4). The fully integrated transmission control control unit calculates the required control current and actuates the torque converter lockup clutch control solenoid valve which influences the position of the torque converter lockup clutch regulating valve (precontrol). The clutch pressure in the torque converter lockup clutch depends on the regulating valve position and thus on the regulating valve geometry.

The actual slip is determined by the comparison of engine speed with turbine speed. If necessary, post-regulation is started by the fully integrated transmission control control unit. The clutch pressure in the torque converter lockup clutch can be increased or reduced by the aftercontrol.

Control state "slipping-open"

In this control state the clutch pressure in the torque converter lockup clutch is reduced in stages until it is eliminated.

The torque converter lockup clutch is not actuated in limp- home mode.