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

GF27.60-P-2002GZ Transmission control, function
- Transmission 722.9


The transmission control is divided into the electronic and hydraulic transmission control functions. Whilst the electronic transmission control takes over the gear selection and adaptation of pressures to the torque to be transmitted, the power supply of the transmission is controlled via the hydraulic elements of the electrohydraulic controller 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 fully integrated transmission control (VGS) makes possible precise adaptation of pressures to the respective operating conditions and to the engine output during the shift phase which results in a significant increase in shift quality. The engine speed limit can be reached in the individual gears at full throttle and kick down.

The shifting range can be altered in the forward gears while driving. The fully integrated transmission control (VGS) prevents the driver revving the engine too high, however, by means of a downshift safeguard. Furthermore, the fully integrated transmission control (VGS) provides the advantage of flexible adaptation to various vehicle and engine versions.

Model 164.120/122/128/176/186 except code (430) Off road package
The driver can activate or deactivate the off road program. These also provide different gear ratios for reverse gear.

Model 164.120/122/128/176/186 with code (430) Off road package, model 164.822/828/871/886
Reverse gear "R" with the ratio used in the transmission mode "S" is available to the driver.

Model 261.022/066/076/122/166/176
Transmission modes "C" and "S" are available to the driver. These also provide different gear ratios for reverse gear.

Model 164.177, 261.077/177
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 fully integrated transmission control (VGS) control unit (Y3/8n4) monitors and shifts depending on:
^ Vehicle speed
^ Gear selector switch position
^ Accelerator pedal position
^ off road program activated or deactivated, model 164.120/122/128/175/186 except code (430) Off road package
^ Transmission mode, model 164.120/122/128/175/186 with code (430) off road package, model 164.177, model 164.822/828/871/886, model 251.022/065/075/077/122/165/175/177
^ Selected gear, with program selection "M", model 164.177, 251.077/177
^ The state of the transmission
^ Signals on the Controller Area Network bus class C (engine compartment) (CAN-C)