GF27.57-P-1000AHX Oil Supply For Automatic Transmission, Function

GF27.57-P-1000AHX Oil Supply For Automatic Transmission, Function
TRANSMISSION 722.930 up to 31.5.11, 722.931 as of 1.6.11
in MODEL 212.0/ 2

Function requirements for automatic transmission oil supply, general
^ Circuit 87 (connected circuit 15) ON

Oil supply for automatic transmission, general
With the combustion engine running, the oil pump (primary pump) delivers oil to the electrohydraulically actuated automatic transmission. The oil pump drive is provided through the wet clutch's drive spigot. The oil pump is installed in the transmission bell housing behind the wet clutch.

The ECO start/stop function went into service as of AEJ11 (modification year 11) (1.6.2011) with the launch of transmission 722.931.

With code (B03) ECO start/stop function
The electric transmission oil pump also supports the primary pump at low internal combustion engine speeds.

Oil supply for automatic transmission with stopped internal combustion engine (with code (B03) ECO start/stop function)
If with a stopped internal combustion engine, the oil supply fails, all control elements and actuators switch to an unloaded basic status and the automatic transmission power flow stops.
When the internal combustion engine is started, and the oil supply has been built up, the gear position has to be changed from "N" to "D". The resulting time delay between the starting request and the starting period is reduced with the electric transmission oil pump (M42).
The electric transmission oil pump is actuated via the transmission oil auxiliary pump control unit (N89) when switching the internal combustion engine on and off. When the internal combustion engine is switched off, the electric transmission oil pump takes over the oil supply of the control elements and actuators of the automatic transmission.