Manual drive mode selection, function - GF27.60-P-3011RT

TRANSMISSION 722.9 in MODEL 251.0/1 up to Model Year 8

Fig 1: Identifying Manual Drive Mode Selection Function Diagram

Courtesy of MERCEDES-BENZ USA

With the DIRECT SELECT gear selector switch (S16/13) and transmission mode switch (N72/1s32) it is possible to adapt the automatic gearshift sequence to suit specific operating conditions. Although the shift range can be changed in the forward gears while driving, the electronic transmission control prevents a gearshift if the engine speed is too high.

Transmission modes except model 251.077/177

The driver can choose between transmission mode "C" and transmission mode "S".

In position "C" (comfort program) of the transmission mode switch compared to position "S" (sport program) a longer overall ratio and therefore a lower output torque is available when driving forwards and reversing. This allows the vehicle to move off more gently. In addition, the gears are not driven to maximum revs.

Transmission modes on model 251.077/177

The driver can choose between the transmission mode "C", transmission mode "S" and transmission mode "M".

In position "M" (Manual program) of the transmission mode switch all forwards gears can be shifted directly by operating the following steering wheel shift buttons:

Steering wheel gear shifter MINUS (S110/1), on model 251.177
Steering wheel gear shifter PLUS (S111/1), on model 251.177

A shift which would result in an unacceptably high or low rotational speed is not carried out.

Gear selector switch, component description		GF27.19-P-5148GZ
Intelligent servo module (ISM) component description		GF27.19-P-4015RT
VGS control unit, component description		GF27.19-P-4016RT
Steering wheel gear shifter component description	Model 251.022/065/075/122/165/175	GF27.19-P-1201RT
	Model 251.077/177	GF27.19-P-1201GZA