Component description for intelligent servo module for DIRECT SELECT - GF27.19-P-4020AHS

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

Automatic transmission viewed from left

Location

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

Fig 1: Identifying Intelligent Servo Module For Direct Select

Courtesy of MERCEDES-BENZ USA

Task

The task of the intelligent servo module for DIRECT SELECT is subdivided into the following projects:

General
Input and output signals

General

The driver gear range requirement "P, R, N, D" is not transmitted to the transmission via a rod (mechanical connection) by the control but by means of an electronic connection. This electronic connection consists of the DIRECT SELECT gear selector switch (S16/13) and the intelligent servo module for DIRECT SELECT. The overall system is described as "DIRECT SELECT gearshift". The intelligent servo module for DIRECT SELECT controls the main motor and the emergency motor.

The intelligent servo module for DIRECT SELECT is flashable. The software of the intelligent servo module for DIRECT SELECT can be updated.

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.

The BAS release switch (A7/7s1) on Model 221 is replaced as of 2.6.09 and on model 216 as of 1.9.10 by the brake light switch (S9/1). With code (233) DISTRONIC PLUS and code (239) ART Plus Light, the BAS release switch is still used.

Control Area Network (data bus/CAN bus) (CAN) input signals

Wheel speeds and position of BAS release switch or brake light switch, from ESP control unit (N47-5) through the chassis CAN (CAN E) and drive train CAN (CAN C)
Request to engage gear selector switch position "P" or "N", from EIS [EZS] (N73) via chassis CAN and drive train CAN
"Circuit 54 ON" feedback as description for park pawl function, from front SAM control unit with fuse and relay module (N10/1) via the interior CAN (CAN B) and central gateway control unit (N93), chassis CAN and drive train CAN
Specified position of range selector lever, from fully integrated transmission control unit (VGS) (Y3/8n4) via drive train CAN

CAN output signals

Actual position of range selector lever (with "circuit 15 ON") to fully integrated transmission control unit (VGS), via drive train CAN
Gear selector switch position to the instrument cluster (A1), via drive train CAN and chassis CAN

Shown up to 31.8.08

Fig 2: View Of Intelligent Servo Module For Direct Select

Courtesy of MERCEDES-BENZ USA

Shown as of 1.9.08

Fig 3: Intelligent Servo Module For Direct Select Function Diagram

Courtesy of MERCEDES-BENZ USA

Function

The main motor (30) is actuated and the worm shaft (33) is turned via the drive gears (39) (up to 31.8.08) or via the drive belts (42) and the two drive pulleys (41) (as of 1.9.08). The slider (32) moves into the required position and the range selector lever (35) assumes the specified position.

The actual position is recorded by the angle sensor (36) and passed on to the fully integrated transmission control unit (VGS) via drive train CAN.

With "circuit 15 ON" the intelligent servo module for DIRECT SELECT passes on the gear selector switch position transmitted by the fully integrated transmission control unit (VGS) to the gear indicator (A1p12). With "circuit 15 OFF" the intelligent servo module for DIRECT SELECT passes on the gear selector switch position transmitted by the steering column tube module (N80) to the gear indicator.

With "Circuit 15 OFF" and the vehicle at a standstill, gear selector switch position "P" or "N" is engaged as soon as the transmitter key (A8/1) is pulled out of the EZS control unit.

For vehicles with code (889) Keyless Go the request of gear selector switch position "P", with "circuit 15 OFF" and the vehicle at a standstill, takes place as soon as the driver door is opened. If gear selector switch position "N" is engaged before "Circuit 15 OFF" and the driver door is opened after "Circuit 15 OFF", gear selector switch position "N" remains engaged.

	Wiring diagram for intelligent servo module (ISM) control unit	A80	Model 216	PE27.60-P-2101-97CAA
		A80	Model 221	PE27.60-P-2101-97SAA