GF27.60-P-2002SXA Transmission Control, Function

GF27.60-P-2002SXA Transmission control, function
- Transmission 722.6


The transmission control is subdivided into electrical and hydraulic functions. Whilst the electronic transmission control (ETC) takes over gear selection and the adaptation of pressures to the torque to be transmitted, the power supply of the transmission 722.6 is controlled via hydraulic elements of the electrohydraulic control unit. The oil supply to the hydraulic elements, such as the hydrodynamic torque converter, the shift elements and the hydraulic transmission control, is provided by way of an oil pump connected to the torque converter. The electronic transmission control (ETC) makes possible a precise adaptation of pressures to the respective operating conditions and to the engine output during the gearshift phase, resulting in a significant improvement in shift quality. It is possible to reach the engine rpm limit in the individual gears using full throttle and kick down.

The shift range can be changed in the forward gears while driving. The electronic transmission control prevents an unacceptably high engine speed by a downshift security device. Furthermore ETC offers the advantage of a flexible adaptation to various vehicle and engine versions.

The driver can choose between 3 transmission modes "S" (sport program), "C" (comfort program) and "M" (manual program). These also provide different gear ratios for reverse gear.

The ETC [EGS] control unit (N15/3) monitors and shifts depending on:
^ Vehicle speed
^ Gear selector switch position
^ Accelerator pedal position
^ Driving program selection
^ Condition of transmission 722.6
^ Selected gear, with transmission mode selector "M"
^ Signals on the drive train CAN