Torque converter lockup clutch control, function - GF27.20-P-3002N
TRANSMISSION 722.9 in MODEL 171.4, 203, 230 up to Model Year 8
TRANSMISSION 722.9 in MODEL 209, 211, 215, 219, 220
TRANSMISSION 722.9 in MODEL 463.303/340/341
The clutch pressure in the torque converter lockup clutch is derived from the working pressure through the torque converter lockup clutch regulating valve. The regulating valve position is influenced by the torque converter lockup clutch control solenoid valve (VGS) (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 (VGS) control unit (Y3/8n4). The fully integrated transmission control (VGS) control unit (Y3/8n4) calculates the required control current and actuates the torque converter lockup clutch control solenoid valve (VGS) (Y3/8y8) which influences the position of the torque converter lockup clutch regulating valve (pre-control). 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 the turbine speed. If necessary, a post-regulation is introduced by the fully integrated transmission control (VGS) control unit (Y3/8n4). The clutch pressure in the torque converter lockup clutch can be increased or reduced by post-regulation.
Control state "slipping-open"
In this control state the clutch pressure in the torque converter lockup clutch is reduced in stages. In this process a constantly progressive operation is involved which is moved along a time ramp from the initial value to zero until the clutch pressure in the torque converter lockup clutch is reduced.
The torque converter lockup clutch is not actuated in limp-home mode
| Torque converter lockup clutch control pressure, function | GF27.60-P-3019N |
Torque converter, function - GF27.20-P-5100-02N
Transmission 722.9 in model 171.4, 203, 209, 211, 215, 219, 220, 230, 463.303/340/341
Scheme 154
Torque converter, function
When the vehicle is stationary and at idle speed, it is the task of the torque converter to reduce the power flow between the engine and automatic transmission to a minimum. Furthermore, it serves to amplify engine torque and to continuously match rotational speed and torque when starting off.
The impeller (4) is connected to the engine and turbine wheel (2) is connected to the transmission input shaft. The stator (3) is connected to the transmission housing via a freewheel and the stator shaft.
The oil in the torque converter is continuously exchanged so that heat generated during the operating phase can be drawn away by the transmission oil cooler
Torque converter, location/task/design/function - GF27.20-P-5100N
TRANSMISSION 722.9 in MODEL 171.4, 203, 230 up to Model Year 8
TRANSMISSION 722.9 in MODEL 209, 211, 215, 219, 220
TRANSMISSION 722.9 in MODEL 463.303/340/341
Scheme 155
| Torque converter, location | The torque converter is rigidly bolted to the driven plate in the torque converter housing. | |
|---|---|---|
| Torque converter, task | When the vehicle is stationary and at idle speed it reduces the power flow between the engine and automatic transmission to a minimum; when starting off it serves engine torque multiplication and continuous RPM/torque adjustment. | |
| Torque converter, design | The impeller (4) is connected to the engine and the turbine wheel (2) to the transmission input shaft. The stator (3) is connected to the transmission housing via a freewheel and stator shaft (8). | |
| Torque converter, function | GF27.20-P-5100-02N |
Torque converter lockup clutch, function - GF27.20-P-5101-02N
Transmission 722.9 in model 171.4, 203, 209, 211, 215, 219, 220, 230, 463.303/340/341
Scheme 156
Function
With an actuation triggered by the fully integrated transmission control (VGS) control unit (Y3/8n4) oil pressure controlled by the torque converter lockup clutch control solenoid valve (VGS) (Y3/8y8) is lead through the drive shaft (1) to the pressure chamber behind the piston (16d). The piston (16d) compresses the clutch pack (16c) and therefore enables direct torque transmission between the impeller (4) and turbine wheel (2).
The torque converter lockup clutch is engaged in all gears depending on engine speed and load.
The torsional damper damps the vibrations coming from the engine. This improves comfort for the driver and saves wear and tear on the mechanical components of the transmission.
Location/task/design/function of torque converter lockup clutch - GF27.20-P-5101N
TRANSMISSION 722.9 in MODEL 171.4, 203, 230 up to Model Year 8
TRANSMISSION 722.9 in MODEL 209, 211, 215, 219, 220
TRANSMISSION 722.9 in MODEL 463.303/340/341
Scheme 157
| Torque converter lockup clutch, location | The torque converter lockup clutch is integrated in the torque converter. | |
|---|---|---|
| Torque converter lockup clutch, task | To minimize the power losses of the torque converter by reducing converter slip, to reduce engine speed as a result and to improve the efficiency of the transmission. | |
| Torque converter lockup clutch, design | The external plate carrier (16a) is connected to the impeller (4) via the torque converter housing (17). The internal plate carrier (16b) is connected to the turbine wheel (2). | |
| Torque converter lockup clutch, function | GF27.20-P-5101-02N |
Torque converter lockup clutch control pressure, function - GF27.60-P-3019N
TRANSMISSION 722.9 in MODEL 171.4, 203, 230 up to Model Year 8
TRANSMISSION 722.9 in MODEL 209, 211, 215, 219, 220
TRANSMISSION 722.9 in MODEL 463.303/340/341
The torque converter lockup clutch is operated at specified slip speeds. In order to make this possible, the variable control pressure has to be applied to the torque converter lockup clutch regulating valve.
The torque converter lock-up clutch control pressure is adapted to the respective operating condition via the torque converter lockup clutch control solenoid valve (VGS) (Y8/8y8) which is actuated by the fully integrated transmission control (VGS) control unit (Y3/8n4).
| Control solenoid valve, location/task/design/function | GF27.19-P-5111N |
|---|---|
| Torque converter lockup clutch, location/task/design/function | GF27.20-P-5101N |
| VGS control unit, location/task | GF27.19-P-4013N |