(Component Description For Fully Integrated Transmission Control Unit - GF27.60-P-5165AND)

Transmission 725.0 (except 725.017/066/096) in model 217, 222 

View of fully integrated transmission control controller unit (Y3/8) from above 

Courtesy of MERCEDES-BENZ USA

Location 

The fully integrated transmission control unit is integrated in the fully integrated transmission control controller unit which is located in the bottom of the automatic transmission.

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 fully integrated transmission control unit (VGS) is flashable i.e. the complete software in the control unit can be changed (replaced). The software required for control unit programming is stored on the diagnosis software DVD.

CAN bus 

The fully integrated transmission control unit is connected via the drive train CAN (CAN C1) 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 30
• Emergency-P from electronic ignition lock control unit (N73)
• Turbine wheel rpm sensor (Y3/8n1)
• Internal transmission rpm sensor (Y3/8n2)
• Output shaft rpm sensor (Y3/8n3)
• Transmission oil temperature sensor (Y3/8s2) (integrated into fully integrated transmission control unit)
• Park pawl position sensor (Y3/8s4)
• Pressure sensor (Y3/8b5)

Direct output signals 

• Electric auxiliary oil pump (M42)
• Park pawl lift solenoid (Y3/8l1)
• Lubrication pressure solenoid (Y3/8y12)
• K81 clutch control solenoid (Y3/8y13)
• K38 clutch control solenoid (Y3/8y14)
• K27 clutch control solenoid (Y3/8y15)
• B08 multidisk brake control solenoid (Y3/8y16)
• B05 multidisk brake control solenoid (Y3/8y17)
• B06 multidisk brake control solenoid (Y3/8y18)
• Working pressure solenoid (Y3/8y19)
• Torque converter lockup clutch solenoid (Y3/8y20)

CAN input signals 

Instrument cluster (A1) 

• Vehicle speed signal

Electronic ignition lock control unit (N73) 

• Electronic ignition lock status
• Release of drive authorization system stage 4 (FBS4)
• "Key-P function" request
• Circuit 50 signal, influencing fault storage
• Diagnostic CAN interface (CAN D) for diagnostic connector (X11/4)

Electronic Stability Program control unit (N30/4) 

• 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, automatic 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®) requested shift into "N", interruption of power flow
• Braking torque status, change of shift strategy, brake vehicle, automatic transmission shifts down earlier.
• ESP® specified torque, torque reduction or torque increase
• Vehicle speed signal

Steering column tube module control unit (N80) 

• Steering wheel downshift button signal (S110/1)
• Steering wheel upshift button signal (S111/1)
• DIRECT SELECT lever signal (S1613)

CDI control unit (N3/9) (with diesel engine) or ME-SFI [ME] control unit (N3/10) (with gasoline engine) 

• Requests for catalytic converter heating
• Shift request
• Selector lever position
• Transmission mode selection
• Engine torque
• Engine coolant temperature
• Engine speed
• Engine load
• Kickdown
• Rpm limitation ACTIVE
• Engine management limp-home mode
• Status of engine management
• Drive train operational
• Engine running status

Trailer recognition control unit (N28/1) (for code 550 (Trailer hitch)) 

• Trailer recognition signal

Audio/COMAND control panel (A40/9) (up to model year 2018 with code 446 (Touchpad only)) 

• Drive program button status (A40/9s8) (up to model year 2018)
• DYNAMIC SELECT switch status (A40/9s19) (as from model year 2018)

Lower control panel (N72) (as from model year 2018 with code 446 (Touchpad only)) 

• DYNAMIC SELECT switch status (N72s19) (as from model year 2018)

Left front door control unit N69/1 (for vehicles with CODE 889 (KEYLESS-GO)) 

• Status of left front door

CAN output signals 

Instrument cluster 

• Selector lever position for gear indicator symbol
• Program selector switch for transmission mode display symbol

CDI control unit or ME-SFI control unit 

• Drive position
• Transmission mode
• Actual gear, target gear
• Engine torque reduction request
• Starter enable in selector lever position "P", "N"
• Target engine speed in neutral (for actuation of torque converter lockup clutch)
• Status of torque converter lockup clutch
• Transmission limp-home mode

Electronic Stability Program control unit 

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

Wiring diagram for fully integrated transmission control unit

PE27.19-P-2103-97SEC