Component description for fully integrated transmission control unit - GF27.60-P-5165AHL

TRANSMISSION 722.9 (except 722.930/931) in MODEL 212 

Location 

The fully integrated transmission control unit (Y3/8n4) is integrated into the fully integrated transmission control controller unit (Y3/8), which is located at the bottom in the transmission.

Fully integrated transmission control controller unit (Y3/8) viewed from above, shown on fully integrated transmission control 4 (VGS4-0, as of YoM 12) 

Task 

General 

The fully integrated transmission control unit determines the current operating condition of the vehicle and actuates all gear change sequences taking shifting comfort and the driving situation into consideration.

Flash programming 

The transmission control system in the control unit for the fully integrated transmission control (VGS) is flashable i.e. the complete software in the control unit can be changed (replaced). The software required to program the control units is stored on the Star Diagnosis software DVD.

CAN data bus 

The fully integrated transmission control unit is connected via the drivetrain CAN (CAN C) to the vehicle's CAN network, and exchanges data with other control units.

Input and output signals 

The following input signals are evaluated by the fully integrated transmission control unit and the appropriate output signals are generated:

• Direct input signals 
• Direct output signals 
• CAN input signals 
• CAN output signals 

Direct input signals 

• Circuit 31
• Circuit 87
• Turbine wheel rpm sensor (Y3/8n1)
• Internal transmission rpm sensor (Y3/8n2)
• Output shaft rpm sensor (Y3/8n3)
• Selection range sensor (Y3/8s1)
• Transmission oil temperature sensor (Y3/8s2) (integrated in the fully integrated transmission control unit)

Direct output signals 

• Working pressure control solenoid valve (Y3/8y1)
• Clutch control solenoid valve K1 (Y3/8y2)
• Clutch control solenoid valve K2 (Y3/8y3)
• Clutch control solenoid valve K3 (Y3/8y4)
• Multidisk brake control solenoid valve B1 (Y3/8y5)
• Multidisk brake control solenoid valve B2 (Y3/8y6)
• Multidisk brake control solenoid valve B3 (Y3/8y7)
• Control solenoid valve for torque converter lockup clutch (Y3/8y8)

Steering column tube module control unit (N80) 

• Signal for steering wheel downshift button (S110/1) (with code (428) Steering wheel shift paddles)
• Signal for steering wheel upshift button (S111/1) (with code (428) Steering wheel shift paddles)

CDI control unit (N3/9) or ME-SFI [ME] control unit (N3/10) 

Requests for catalytic converter heating

Switching request

• Engine torque
• Engine coolant temperature
• Engine speed
• Engine load
• Kickdown
• Engine speed limitation active
• Limp-home mode engine control

Trailer recognition control unit (N28/1) 

• Trailer recognition signal

Front SAM control unit with fuse and relay module (N10/1) 

• Diagnostic CAN (CAN D) interface

Transmission oil auxiliary pump control unit (N89) 

• Actual value of on/off ratio (related actual current value)
• Diagnostic data

CAN output signals 

Instrument cluster (A1) 

• Selector lever position for gear display (A1p12)
• Multifunction display (A1p13)
• Program selection for transmission mode display (A1p16)
• Actuation of indicator lamp for engine diagnosis (A1e58)

CDI control unit (N3/9) or ME-SFI [ME] control unit (N3/10) 

• Drive position
• Transmission mode
• Actual gear, target gear
• Engine torque reduction request
• Starter enable in selector lever position "P", "N"
• Engine idle specified speed (for actuation of the torque converter lockup clutch)
• Status of torque converter lockup clutch
• Emergency operation transmission control

Electronic Stability Program control unit (N30/4) or Premium Electronic Stability Program control unit (with code (233) DISTRONIC PLUS) (N30/7) 

• Wheel torque factor, overall gear ratio
• Actual gear, target gear
• Transmission variant, recognition of basic variants, difference in gear ratios

CAN input signals 

Intelligent servo module for DIRECT SELECT (A80) 

• Selector lever position
• Transmission mode selection

Electronic ignition lock control unit (N73) 

• Drive authorization system (DAS) enable
• "Key-P function" request
• Circuit 50 signal, influencing fault storage

Electronic Stability Program control unit (N30/4) or Premium Electronic Stability Program control unit (with code (233) DISTRONIC PLUS) (N30/7) 

• Wheel speeds and direction of rotation, substitute values in the event of failure of the output shaft rpm sensor
• Adjusted braking torque, change of shift strategy, brake the vehicle, transmission shifts down earlier
• Vehicle lateral acceleration at center of gravity, adaptation of shift strategy, detection of dynamic driving style
• Cruise control operation, special shifting strategy
• Electronic Stability Program (ESP) desired shift operation into "N", power flow interruption
• Brake light switch (S9/1), change of shift strategy, brake the vehicle, transmission shifts down earlier
• ESP specified torque, torque reduction or torque increase

Transmission oil auxiliary pump control unit (N89) 

• Specified value of on/off ratio (related specified current value)

The gear limitation is replaced by the function "Short-term M mode". The short-term M program is a temporary program that is activated when the steering wheel gearshift buttons or the DIRECT SELECT lever are operated. Pressing in the positive (+) direction triggers an upshift and pressing in the negative (-) direction triggers a downshift, insofar as this is permissible. If not, the current gear is maintained. After a specified time window, this function deactivates again automatically. The time activated can be extended by undershooting a minimum speed (e.g. stopping), upon recognition of a lateral acceleration by the yaw rate sensor for lateral and longitudinal acceleration (B24/15) or if the vehicle is coasting. If none of the stated criteria are active anymore, the M mode remains active for a prescribed remaining time. After this remaining time expires, the initial shift mode is returned to.

The driver can prematurely cancel the short-term M mode through specific actions, e.g. if he/she operates and holds the steering wheel upshift button or the DIRECT SELECT lever (S16/13) in the "positive" direction, changes the gear range or changes the transmission mode. If one of these preconditions is met, a switch is made back to the initial shift program.

As of model refinement 13, a gearshift recommendation is also shown in the instrument cluster. This is part of the short-term M mode.

Wiring diagram for electronic transmission control (ETC) control unit

PE27.19-P-2101-97DAB