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

GF27.60-P-2000AHW Gear shift, function
- TRANSMISSION 722.902/906/907/960/962/963/964/998/999 in MODEL 204.0
- TRANSMISSION 722.906/960/962/964 in MODEL 204.9

Function requirements
^ Circuit 87 ON
^ Circuit 61 ON
^ Engine speed from CDI control unit (N3/9) (with diesel engine) or from ME-SFI control unit (N3/10) (with gasoline engine)
^ Transmission not in limp-home mode
^ Drive train CAN (CAN C) signals

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 the selector lever positions "P", "R", "N", "D" to the fully integrated transmission control unit 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). 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.

Function sequence
The function sequence is described in the following steps:
^ Function sequence for upshift and downshift
^ Function sequence of gearshift 1 to 2

Function sequence for upshift and downshift
In transmission modes Sport "S" and Comfort "C" by operating the selector lever (touch mode (+/-)) or downshift steering wheel gearshift button (S110/1) or upshift steering wheel gearshift button (S111/1), with code (428) Steering wheel shift paddles, the driver can select the following functions:
- Single operation towards "2 activates the function of gear limitation or touch shift (if engine speed permits, the transmission shifts down into the gear, which is one gear below the gear in current use).
- By operating and holding towards "2 the function "Shift into optimum gear is selected (the gear is selected which enables the best acceleration of the vehicle).
- Single operation towards "+" with selected gear limitation causes an increase in shift limitation by one gear (e.g. from 3 to 4).
- Single operation towards "+" with gear range "D" conveys an upshift request to the transmission (the transmission upshifts depending on the driving situation).
- By operating and holding towards "+" gear limitation is canceled completely (shift to "D").

In transmission mode Comfort "C" in comparison to transmission mode Sport "S" 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 except code (494) USA version or model 204.9 with code (430) Offroad 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 except code (494) USA version or model 204.9 with code (430) Offroad package and code (952) Sport package) is no longer active after a status change from "circuit 15 OFF" to "circuit 15 ON". The vehicle then always starts off in the transmission mode last selected ("S" or "C").

Function sequence of gearshift 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 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).

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.