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GF27.19-P-4020AHX Intelligent Servo Module For Direct Select, Component Description




GF27.19-P-4020AHX Intelligent Servo Module For DIRECT SELECT, Component Description
TRANSMISSION 722.930 up to 31.5.11, 722.931 as of 1.6.11
in MODEL 212.0/ 2





View of automatic transmission from left (without code (B03) ECO start/stop function)

A80 Intelligent servo module for DIRECT SELECT

Location
The intelligent servo module for DIRECT SELECT is mounted on the left of the transmission housing.

Task
General
The driver's gear range request "P", "R", "N", "D" is not transmitted from the control to the transmission via a rod (mechanical connection) but by means of an electronic connection ("wire"). This electronic connection consists of the DIRECT SELECT INTERFACE (N150) and the intelligent servo module for DIRECT SELECT. The overall system is called "Shift-by-wire". The intelligent servo module for DIRECT SELECT controls the main motor and the emergency motor.

Input and output signals
Signal inputs and outputs
Direct input signals
- Circuit 30
- Circuit 31
- Power supply for emergency motor

The intelligent servo module for DIRECT SELECT measures the position of the eccentric shaft via the eccentric shaft position sensor and the actual position of the range selector lever via the angle sensor.

Control Area Network (data bus/CAN bus) (CAN) input signals
- Wheel speeds and status of service brake from Premium Electronic Stability Program control unit (N30/7)
- Request to engage selector lever position "P" or "N", from electronic ignition lock control unit (N73)
- "Circuit 54 ON" feedback as additional information for parking lock function, from front SAM control unit with fuse and relay module (N10/1)
- Specified position of range selector lever, from fully integrated transmission control unit (Y3/8n4)

CAN output signals
- Actual position of range selector lever (with "Circuit 15 ON"), to fully integrated transmission control unit

The ME-SFI [ME] control unit (N3/10) is the interface between the drive train CAN (CAN C) and chassis CAN (CAN E).





Shown in range selector lever position "N"
30 Main motor
31 Emergency motor
32 Slider
33 Worm shaft
34 Eccentric shaft
35 Range selector lever
36 Angle sensor
40 Eccentric shaft position sensor
41 Drive pulleys
42 Drive belt

Function
When the main motor is actuated, the worm shaft is turned via the drive belt and the two drive pulleys. The carriage moves to the required position and the range selector lever assumes the specified position selected.
The actual position is detected by the angle sensor and sent via the drive train CAN to the fully integrated transmission control unit.
With "Circuit 15 ON", the intelligent servo module for DIRECT SELECT transfers the selector lever position transmitted by the fully integrated transmission control unit, to the gear indicator (A1p12). At "Circuit 15 OFF", the intelligent servo module for DIRECT SELECT sends the selector lever position sent by the steering column tube module control unit (N80), to the gear indicator.

With "circuit 15 OFF" and vehicle standstill, selector lever position "P or N" is engaged, as soon as the transmitter key (A8/1) is removed from the electronic ignition lock control unit.
On vehicles with code (889) Keyless Go, the request for selector lever position "P", with "circuit 15 OFF" and the vehicle at a standstill is made as soon as the driver door is opened.
If selector lever position "N" is engaged before "Circuit 15 OFF" and the driver door is opened after "Circuit 15 OFF", selector lever position "N" remains engaged.