Component Description For Intelligent Servo Module For Direct Select - GF27.19-P-4020AHG
Transmission 722.9 in model 463 as of model year 2013
Automatic transmission viewed from left
Location
The intelligent servo module for DIRECT SELECT is mounted on the left of the transmission housing.
Tasks
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 known as a "shift-by-wire gearshift".
The intelligent servo module for DIRECT SELECT receives the signals from the angle sensor which records the actual position of the range selector lever and eccentric shaft. The intelligent servo module for DIRECT SELECT controls the main motor and the emergency motor.
The tasks are subdivided as follows:
- Reading in of signals
- Evaluation of input factors
- Sending signals
Reading in of signals
The intelligent servo module for DIRECT SELECT reads in, among other things, the following signals via the drivetrain CAN (CAN C):
- Wheel speeds
- Status of service brake
- Request for park pawl "P"
- Request for gear ranges "R", "N", "D"
- Specified position of range selector lever
- Status of park pawl button (S76/14)
The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).
Evaluation of input factors
The input factors that have been read in are evaluated by the integrated microprocessor whereupon the relevant signals are then issued.
Sending signals
The intelligent servo module for DIRECT SELECT sends, among other things, the following signals via the drivetrain CAN:
- Actual position of range selector lever (at circuit 15 ON)
- Selector lever position
The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).
Shown in range selector lever position "N"
Function
The main motor (30) is actuated and the threaded rod (33) is turned by the drive belt (42) and the two drive pulleys (41). The carriage (32) moves to the required position and the range selector lever (35) assumes the specified position selected.
The actual position is detected by the angle sensor (36) and sent via the drivetrain CAN to the fully integrated transmission control unit (Y3/8n4).
| Wiring diagram for intelligent servo module (ISM) control unit | Transmission 722.9 in model 463 as of model year 2013 | PE27.60-P-2101-97ZGA | |
| Transmission 722.9 in model 463.342 as of model year 2017 | PE27.60-P-2101-97ZBA |