GF27.60-P-2000AHW Shift Operation, Function

GF27.60-P-2000AHW Shift Operation, Function
TRANSMISSION 722.9 (except 722.930) in MODEL 204.0 as of model year 2009 /YoM 08
TRANSMISSION 722.9 (except 722.930) in MODEL 204.2 as of model year 2009 /YoM 08
TRANSMISSION 722.9 (except 722.930) in MODEL 204.3
TRANSMISSION 722.9 in MODEL 204.9

Function requirements for shift operation, general
^ Circuit 87 ON
^ Circuit 61 ON
^ Engine speed from CDI control unit (N3/9) (with diesel engines) or ME-SFI control unit (N3/10) (with gasoline engines)
^ Transmission not in limp-home mode
^ Signals from drive train CAN (CAN C)

Shift operation, general
The fully integrated transmission controller unit (Y3/8) converts the electrical signals coming from the fully integrated transmission control unit (Y3/8n4) into hydraulic signals.
The electronic selector lever module control unit (N15/5) passes on selector lever positions "P", "R", "N" and "D" to the fully integrated transmission control unit via the drive train CAN taking into account various pieces of information.
The electronic selector lever module control unit changes the position of the selector range lever which is transmitted mechanically to the selection range sensor (Y3/8s1).

The shift range is displayed in the instrument cluster (A1). The signal flow runs from the fully integrated transmission control unit over the drive CAN with the CDI control unit interface (with diesel engines) or the ME-SFI [ME] control unit (with gasoline engines) to the instrument cluster.
Although the shift range can be changed in the forward gears while driving, the fully integrated transmission control unit prevents a shift operation if the engine speeds are too high or too low.

Changeover from Comfort ("C") transmission mode to Economy ("E") transmission mode
As of model year 11 /YoM 10, the labeling on the automatic transmission mode button (S16/12) and the display in the instrument cluster will be changed from Comfort ("C") transmission mode to Economy ("E") transmission mode.

Function sequence for shift operation
The function sequence is described in the following steps:
^ Function sequence for shifting up and down
^ Function sequence for shift operation, gear 1 to 2

Function sequence for shifting up and down
In the Sport ("S") and Comfort ("C") / Economy ("E") transmission modes, the driver can select the following functions by operating the selector lever (touch mode (±)) or steering wheel downshift button (S110/1) or steering wheel upshift button (S111/1):
One press towards "-" activates the gear limitation or touchshift 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").

Compared to the Sport ("S") transmission mode, the Comfort ("C") / Economy ("E") transmission mode has a shorter shift range (shifting at low engine speed) and therefore a lower torque is available when starting off forwards and starting off in reverse.
This enables a gentler start-off as the gears are not driven to the limit.
In transmission mode Manual "M" (model 204.077/277, model 204.0/2, model 204.3 except code (494) USA version or model 204.9 with code (430) Off-road package and code (952) Sport package) the individual gears "1", "2", "3", "4", "5", "6", "7" can be shifted directly via the downshift and upshift steering wheel gearshift buttons.

Reverse gear, park position and neutral can only be selected by way of the electronic selector lever module control unit.

Transmission mode Manual "M" (model 204.077/277, model 204.0/2, model 204.3 except code (494) USA version or model 204.9 with code (430) Off-road package and code (952) Sport package) is no longer active after a change in status from "circuit 15 OFF" to "circuit 15 ON". The vehicle then always starts off in the transmission mode last selected ("S" or "C" / "E").

Function sequence for shift operation, gear 1 to 2
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.
The shift operation can be started by the fully integrated transmission control unit. In the process the multidisk brake B1 is filled with oil and the pressure in the multidisk brake B1 is continuously increased. Simultaneously the pressure in multidisk 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).

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

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.