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Gear shift, function - GF27.60-P-2000AHS

TRANSMISSION 722.9 in MODEL 216.3 as of model year 2009 / YoM 08 

TRANSMISSION 722.9 in MODEL 216.3 (except 216.374) as of Model Year 2011/YoM 10 model refinement package 

TRANSMISSION 722.9 in MODEL 221.0 as of model year 2009 / YoM 08 

TRANSMISSION 722.9 in MODEL 221.0 (except 221.095) 

TRANSMISSION 722.9 in MODEL 221.0 (except 221.074) as of Model Year 2011/YoM 10 

TRANSMISSION 722.9 in MODEL 221.1 as of model year 2009 / YoM 08 

TRANSMISSION 722.9 in MODEL 221.1 (except 221.195) 

TRANSMISSION 722.9 in MODEL 221.1 (except 221.174) as of Model Year 2011/YoM 10 

Function requirements for shift operation, general 

Shift operation, general 

The electric controller unit (VGS) (Y3/8) converts the electrical signals coming from the fully integrated transmission control unit (VGS) (Y3/8n4) into hydraulic signals. The selector lever positions "P, R, N, D" from the DIRECT SELECT gear selector switch (S16/13) are transferred to the chassis CAN (CAN E) by the steering column tube module (N80).

The CDI control unit or ME-SFI control unit transfers the information to the drive train CAN. Taking various information into account, the intelligent servo module for DIRECT SELECT (A80) transfers the selector lever positions to the fully integrated transmission control unit (VGS).

The intelligent servo module changes the position of the selector range lever, which is transmitted to the selection range sensor (VGS) (Y3/8s1).

The shift range is displayed in the instrument cluster (A1). Although the shift range can be changed in the forward gears while driving, the fully integrated transmission control unit (VGS) prevents a shift operation if the engine speed is too high or too low.

Shift operation, function sequence 

The function sequence is subdivided into the following steps:

Function sequence for shifting up and down 

In the Sport "S" and Comfort "C" transmission modes, the driver can select the following functions by pressing the steering wheel gear shifter MINUS (S110/1) and steering wheel gear shifter PLUS (S111/1) with code (428) steering wheel shift paddles:

One press toward "-" activates the gear limitation function (a downshift is made to the gear that lies exactly one below the currently selected one if the engine speed allows).

Pressing and holding towards "-" selects the "Shift to optimal gear" function (the gear which allows the best vehicle acceleration is selected).

One press toward "+" with the gear limitation function selected increases gearshift limitation by one gear (e.g. from 3 to 4). One press toward "+" in gear range "D" sends an upshift request to the transmission (the transmission shifts up if the driving situation allows).

Pressing and holding toward "+" cancels the gear limitation function completely (gearshift to "D").

In transmission mode Comfort "C", the available shift range (shifting at low engine speed) is shorter than in transmission mode "S" resulting in a lower drive torque when starting off in the forward or reverse direction.

This enables a gentler start-off as the gears are not driven to the limit.

In transmission mode Manual "M" (except code (494) USA version), the individual gears "1, 2, 3, 4, 5, 6, 7" can be shifted directly using the MINUS and PLUS steering wheel gear shifter.

The reverse gear, park position and neutral position can only be engaged using the DIRECT SELECT gear selector switch.

IMPORTANTManual transmission mode 

Transmission mode Manual "M" is no longer active after ignition "OFF" → "ON". The transmission always starts in the last selected transmission mode. ("S" or "C").

Function sequence for 1 to 2 shift 

Multidisk brake B2, multidisk brake B3 and multidisk clutch K3 are engaged in 1st gear. When shifting from 1st gear to 2nd gear, multidisk brake B3 is disengaged and multidisk brake B1 is engaged.

This speed adjustment is achieved by the pressure in the multi-disk brake B1 being increased and, if necessary, engine torque being reduced via the CDI control unit or ME-SFI control unit.

The shift operation is started by the fully integrated transmission control unit (VGS). Here, the multidisk brake B1 is filled and the pressure in multidisk brake B1 is increased continuously.

Simultaneously the pressure in multi-disk brake B3 is reduced. This involves a flowing transition. When the 2nd gear torque is reached, the engine speed must be adapted to the 2nd gear level (elevation phase).

IMPORTANT A forced downshift occurs at excessively low RPM and a forced upshift occurs at an excessively high RPM.

When the vehicle is stationary the transmission automatically shifts into 1st gear. It is possible to start off both in 1st or 2nd gear.

REFER TO SYSTEM WIRING DIAGRAMS Electrical function schematic Shift mechanism Model 216 PE27.19-P-2057-97CAB
  Emergency default mode, function   GF27.60-P-3012AHS 
  Engage gear range, function   GF27.60-P-3009AHS 
  Torque converter lockup clutch control, function   GF27.20-P-3002AHS 
  Torque converter lockup clutch control pressure, function   GF27.60-P-3019AHS 
  Working/lubrication/shift pressure, function   GF27.60-P-3024AHS 
  Control valve pressure, function   GF27.60-P-3017AHS 

Gear shift, function-GF27.60-P-2000SX 

TRANSMISSION 722.9 in MODEL 216, 221 up to Model Year 8 

The electrohydraulic controller unit converts electrical signals going out from the fully integrated transmission control (VGS) into hydraulic signals. Faults occurring in the fully integrated transmission control (VGS) are covered by limp-home mode. The limp-home strategy is designed so that the driver can still reach a Mercedes-Benz service operation under extreme conditions.

The gear selector switch positions "P", "R", "N" and "D" are transferred by the steering column module (N80) to the chassis CAN. The ME-SFI [ME] control unit (N3/10) or the CDI control unit (N3/9) (only model 221 with engine 642 or engine 629) convey the information on the drive train CAN. The fully integrated transmission control (VGS) control unit (Y3/8n4) passes on the gear selector lever positions to the intelligent servo module for DIRECT SELECT (A80) taking into account various information.

The intelligent servo module for DIRECT SELECT changes the position of the range selector lever which is passed on mechanically to the selection range sensor (VGS) (Y3/8s1).

Transmission mode "C" or "S" 

Via the following steering wheel shift buttons the shift range up to which it is possible to upshift the transmission is preselected:

Program selection "M" on model 216.371 and model 221 except code (494) USA version, on model 216.377, model 221.077/177 

Program selection "M" is only possible in gear selector switch position "D". The 7 forward gears of the transmission 722.9 can be shifted directly in the process via the following steering wheel shift buttons:

Gear change, function GF27.60-P-3010GZ 
Shift from 1 to 2, function GF27.60-P-4013GZ 
Shifting N to D (1st gear), function GF27.60-P-4014GZ 
Emergency default mode, function GF27.60-P-3012SX 
Manual drive mode selection, function GF27.60-P-3011SX 
Oil level control, function GF27.10-P-3024GZ 
Torque converter lockup clutch control, function GF27.20-P-3002GZ 
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