GF27.60-P-3024AHW Working/Lubrication/Shift Pressure, Function

GF27.60-P-3024AHW Working/Lubrication/Shift Pressure, Function
TRANSMISSION 722.9 (except 722.930) in MODEL 204.0 as of model year 2009 /YoM 08
TRANSMISSION 722.9 (except 722.930) in MODEL 204.2 as of model year 2009 /YoM 08
TRANSMISSION 722.9 (except 722.930) in MODEL 204.3
TRANSMISSION 722.9 in MODEL 204.9

Function requirements for working/lubrication/shift pressure, general
^ Circuit 87 (connected circuit 15) ON
^ Circuit 61 (engine running)

Working/lubrication/shift pressure, general
The oil pressures are separated into:
^ Working pressure
^ Lubrication pressure
^ Shift pressure

Working pressure
The oil pressure produced by the oil pump is converted into working pressure by the working pressure regulating valve.

The level of working pressure depends on the position of the regulating valve and therefore on its geometry.

The position of the working pressure regulating valve is influenced by the working pressure control solenoid valve (Y3/8y1) depending on load and gear. All other pressures required for transmission control are derived from the working pressures.

With model 204.0/2/3/9 as of 1.7.2010
The optimized working-pressure reduction for the new generation of automatic transmissions enables lower braking power and therefore reduces the fuel consumption.

Lubrication pressure
At the working pressure regulating valve excess oil is diverted to the lubrication pressure regulating valve and from there used in a regulated manner for lubrication and cooling of mechanical transmission parts and the torque converter.

In addition the pressure in the torque converter is limited by the level of lubrication pressure.

Shift pressure
The shift pressure (pressure in the multidisk clutch or in multidisk brake) is derived from the working pressure.

The respective control solenoid valve influences the position of the associated regulating valve. In turn the position influences the pressure prevailing in the multidisk brake or in multidisk clutch.

The pressure thus depends on the geometry of the respective regulating valve.

For code (B03) ECO start/stop function
The electric transmission oil pump (M42) safeguards the hydraulic system's oil supply when the internal combustion engine is switched off. This is actuated through the gear oil auxiliary pump control unit (N89).