Component Description For Fully Integrated Transmission Control Unit - GF27.60-P-5165ANF

TRANSMISSION 725.0 in MODEL 166 

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

Fig 1: Fully Integrated Transmission Control Unit Component Location - Transmission 725.0 in Model 166

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.

Tasks 

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 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 C) to the CAN network of the vehicle 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 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 switch control unit 

• 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 speed and direction of rotation, substitute value 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
• Brake light switch (S9/1), change of shift strategy, brake vehicle, automatic transmission downshifts earlier.
• ESP® specified torque, torque reduction or torque increase

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

• 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
• Engine running status

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

• Trailer recognition signal

Transmission mode control panel (N72/4) (without CODE 430 (On & Offroad package)) 

• Transmission mode control

Off-road control panel control unit (N72/3) (with CODE 430 (On & off-road package)) 

• Off-road package transmission mode control (N72/3s1)

Left front door control unit (N69/1) 

• Status of left front door safety catch microswitch (A85s1)

CAN output signals 

Instrument cluster 

• Selector lever position for gear indicator (A1p12)
• Display, multifunction display (A1p13)
• Program selection for transmission mode display in multifunction display

CDI control unit or ME-SFI [ME] control unit 

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

ESP® control unit 

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

Electronic ignition switch control unit 

• Diagnostic CAN interface to diagnostic connector