Working/lubrication/shift pressure, function - GF27.60-P-3024AHW
TRANSMISSION 722.9 in MODEL 204.0 as of model year 2009/YoM 08
TRANSMISSION 722.9 in MODEL 204.0 as of model year 2012/YoM 11 model refinement package
TRANSMISSION 722.9 in MODEL 204.2 as of model year 2009/YoM 08
TRANSMISSION 722.9 in MODEL 204.2 as of model year 2012/YoM 11 model refinement package
TRANSMISSION 722.9 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
- Lubricating 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 the transmission control are derived from the working pressure.
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.
Lubricating 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 via the lubrication pressure.
Shift pressure
The shift pressure (pressure in the multi-disk clutch or in multi-disk 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 multi-disk brake or in multi-disk 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).
| Overview of system components for automatic transmission (AT) | GF27.10-P-9992AHW |