Working/lubrication/shift pressure, function - GF27.60-P-3024ACS

TRANSMISSION 722.649 in MODEL 216.3 as of Model Year 09 /Modification Year 08 

TRANSMISSION 722.649 in MODEL 221.1 as of Model Year 09 /Modification Year 08 

Function requirements for working/lubrication/shift pressure, general 

• Circuit 87 ON
• Circuit 61 (engine running)

Working/lubrication/shift pressure in general 

The oil pressures are separated into:

• Working pressure 
• Lubricating pressure 
• Shift pressure 

Working pressure 

The working pressure supplies pressure to the hydraulic control and transmission elements.

The working pressure is the highest hydraulic pressure in the entire hydraulic system. The level of working pressure is regulated at the working pressure regulating valve depending on current load and the gear engaged. All other pressures required for the transmission control are derived from the working pressure.

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 level of shift pressure is determined by the shift pressure control solenoid valve (Y3/6y2) and shift pressure regulating valve. It regulates the pressure in the engaging actuator during the shift phase. The shift pressure together with the modulating pressure determines the pressure reduction regulated by the overlap regulating valve on the closing shift element and initializes the 2nd. gear in limp-home mode.