VGS control unit, component description - GF27.19-P-4016CWQ

TRANSMISSION 722.9 in MODEL 204.0 up to Model Year 2008 

Location 

The fully integrated transmission control control unit is integrated in the fully integrated transmission control controller unit and located in the automatic transmission.

Task 

The fully integrated transmission control 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.

It receives operating data as internal transmission input signals from the:

• Selection range sensor
• Transmission oil temperature sensor (Y3/8s2), integrated in the fully integrated transmission control control unit
• Turbine wheel rpm sensor
• Internal transmission speed rpm sensor
• Output shaft rpm sensor

The Controller Area Network (data bus/CAN bus) (CAN) also provides a connection to:

• Instrument cluster (A1), via the central-CAN
• Audio/COMAND control panel (A40/9), via the telematics CAN
• Electronic selector lever module control unit (N15/5), via the drive train CAN
• CDI control unit (N3/9), via the drive train CAN
• Electronic Stability Program control unit (N30/4), via the chassis CAN
• Electronic ignition lock control unit (N73), via the chassis CAN
• Steering column module control unit (N80), via the chassis CAN
• Front SAM control unit with fuse and relay module (N10/1), via the chassis CAN

The CDI control unit is the interface between the drive train CAN and chassis CAN, the front SAM control unit with fuse and relay module is amongst others the interface between the chassis CAN and interior CAN and the Electronic Stability Program control unit is the interface to the vehicle dynamics CAN.

The fully integrated transmission control control unit actuates the following control solenoid valves depending on the processed input signals:

• Clutch control solenoid valve K1
• Clutch control solenoid valve K2
• Working pressure control solenoid valve, for load-dependent and gear-dependent working pressure control
• Clutch control solenoid valve K3
• Multidisk brake control solenoid valve B1
• Multidisk brake control solenoid valve B2, also actuates the multidisk brake for the reverse gear
• Multidisk brake control solenoid valve B3
• Torque converter lockup clutch control solenoid valve

Information from other systems which is also processed: 

Selector lever module 

• Transmission mode selection at automatic transmission transmission mode button
• Selector lever position

Electronic Stability Program control unit 

• Signal from BAS release switch (A7/7s1), change of shift strategy, brake the vehicle, the fully integrated transmission control (VGS) shifts down sooner
• Adjusted brake torque, change of shift strategy, brake the vehicle, the fully integrated transmission control shifts down earlier
• ESP request shift into "N" (neutral), power flow interruption, transmission/rear axle
• Cruise control controls, a special shifting strategy for cruise control mode is stored in the fully integrated transmission control control unit
• Vehicle lateral acceleration at center of gravity, adaptation of shift strategy, detection of dynamic driving style
• Wheel speeds and direction of rotation, substitute values in the event of failure of the output shaft rpm sensor

CDI control unit 

• Active downshift for heating up the catalytic converter (TWC)
• Specified gear, and lower/upper limit for heating up the catalytic converter
• Emergency operation of the common rail diesel injection (CDI), the pedal value is limited to approx. 20 %, the driveability of the vehicle is assured
• Engine coolant temperature, used as a substitute value in the event of failure of the transmission oil temperature sensor
• Shift curve offset for heating up the catalytic converter
• Starting off in 1st gear to heat up the catalytic converter
• Engine oil temperature, the shifting restriction is canceled as of a certain value
• Requirement torque for Electronic Stability Program (Electronic-Stability-Program) (ESP), torque reduction or torque increase taking into account directional stability and road adhesion
• Request for torque converter lockup clutch "Open" in the heating up phase of the catalytic converter, to increase engine speed
• Engine idle specified speed, for actuation of the torque converter lockup clutch control solenoid valve
• Engine-speed limitation function active, adaptations are deactivated in the fully integrated transmission control control unit
• Engine speed, for slip calculation of the torque converter lockup clutch control solenoid valve and for the start of pressure calculation by the fully integrated transmission control control unit
• Kickdown
• Pedal value
• Engine torque

Electronic transmission control control unit 

• Enable of stage 3 drive authorization system (DAS 3)
• Request of Key-P function
• Circuit 50, influencing fault memory

Steering column module control unit 

• Signal from steering wheel upshift button (S111/1), with code (428) Steering wheel shift buttons
• Signal from steering wheel downshift button (S110/1), with code (428) Steering wheel shift buttons

Front SAM control unit with fuse and relay module 

• Diagnosis

Information which is output at other systems: 

Instrument cluster (A1) 

• Gear selector switch position and selected shift range for the gear indicator (A1p12)
• Transmission mode selection for the transmission mode display (A1p16)

Electronic Stability Program control unit 

• Wheel torque factor, overall gear ratio
• Actual gear engaged/target gear, i.e. engaged gear, gear to be shifted, can be shown via STAR DIAGNOSIS
• Transmission variant, recognition of basic variants, difference in gear ratios

ME-SFI [ME] control unit (N3/10) 

• Engine torque requests, engine intervention when shifting
• Limp-home mode of fully integrated transmission control
• Starting release in gear selector switch position "P", "N"
• Transmission variant, recognition of basic variants, difference in gear ratios
• Actual gear engaged/target gear, i.e. engaged gear, gear to be shifted, can be shown via STAR DIAGNOSIS
• Status of torque converter lockup clutch

Front SAM control unit with fuse and relay module 

• Diagnosis