ETC [EGS] control unit, component description - GF27.19-P-4018G
TRANSMISSION 722.6 in MODEL 216, 221 up to Model Year 08
Shown on model 221
Networking of components, shown on model 221 except code (494) USA version, except code (219) Distronic (DTR)
The ETC [EGS] control unit determines the instantaneous operating condition of the vehicle and controls all gear change sequences taking into account shift comfort and the driving situation.
It receives operating data as internal transmission input signals from the:
- Starter lockout contact
- Transmission oil temperature sensor
- RPM sensor 2
- RPM sensor 3
The ETC [EGS] control unit takes over the actuation of the solenoid valves for modulating pressure, shift pressure and the gear change. The required pressure, matched to the torque to be transmitted, is calculated from all input signals.
The Controller Area Network (data bus/CAN bus) (CAN) also provides a connection to:
- Instrument cluster, via the central-CAN
- Front central operating unit, via the telematics CAN
- Intelligent servo module for DIRECT SELECT, via the drive train CAN
- ME-SFI [ME] control unit, via the drive train CAN
- DTR controller unit (A89), on vehicles with code (219) Distronic (DTR), via the vehicle dynamics CAN
- ESP control unit, via the chassis CAN
- EIS [EZS] control unit, via the chassis CAN
- Steering column module, via the chassis CAN
- Central gateway control unit, via the chassis CAN
The ME-SFI [ME] control unit is the interface between the drive train CAN and the chassis CAN, the central gateway control unit is amongst others the interface between the chassis CAN and the central CAN, the COMAND controller unit is the interface to the Telematics CAN and the ESP control unit is the interface to the vehicle dynamics CAN.
This involves the processing of the following data from other systems:
Front central operating unit
- Transmission mode selection at transmission modes switch (model 221)
- Transmission mode selection at transmission modes button (A40/9s8) (model 216)
Intelligent servo module for DIRECT SELECT
- Actual position of range selector lever
DTR controller unit, on vehicles with code (219) Distronic (DTR)
- Shift line displacement, brake the vehicle, the electronic transmission control (EGS) shifts down sooner
- Active downshift, brake the vehicle the electronic transmission control shifts down sooner
ESP control unit
- Cruise control regulates, a special shift strategy for cruise control mode is stored in the ETC [EGS] control unit
- ESP request shift into "N" (neutral), power flow interruption, transmission/rear axle
- Adjusted braking torque, change in shift strategy, brake the vehicle, the electronic transmission control shifts down earlier
- 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 RPM sensor 3
- Signal from BAS release switch (A7/7s1), change in shift strategy, brake the vehicle, the electronic (EGS) transmission control shifts down sooner
ME-SFI control unit
- Active downshift for heating up the catalytic converter (TWC)
- Engine torque
- Specified gear, and lower/upper limit for heating up the catalytic converter
- Emergency operation of the ME fuel injection and ignition system (motor electronics) (ME), the pedal value is limited to approx. 20%, the driveability of the vehicle is assured
- Shift curve offset for heating up the catalytic converter
- Engine coolant temperature is used as a substitute value in the event of failure of transmission oil temperature sensor
- Starting off in 1st gear to heat up the catalytic converter
- Engine oil temperature, shift limitation is canceled
- 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" to increase engine speed in the heating up phase of the catalytic converter
- Engine idle specified speed for the actuation of the torque converter lockup clutch
- Kickdown
- Engine speed for slip calculation of torque converter lockup clutch and for the start of pressure calculation by the ETC [EGS] control unit
- RPM limitation function active, adaptations in the ETC [EGS] control unit are switched off
- Pedal value
EIS [EZS] control unit
- Enable of stage 3 drive authorization system (DAS 3)
- Request of Key-P function
- Circuit 50, influencing fault memory
Steering column module, on model 216.376 and 221.176
- Signal from left steering wheel gear shifter
- Signal from right steering wheel gear shifter
- Signal from DIRECT SELECT gear selector switch
Steering column module, on model 221.179
- Signal from steering wheel gear shifter MINUS (S110/1)
- Signal from steering wheel gear shifter PLUS (S111/1)
- Signal from DIRECT SELECT gear selector switch
Central gateway control unit
- Diagnosis
The following information is passed to other systems:
Instrument cluster
- Gear selector switch position and selected shift range for the gear indicator (A1p12)
- Transmission mode selection for the transmission mode display (A1p16)
Intelligent servo module for DIRECT SELECT
- Driver selected gear selector position
- Specified position of range selector lever
DTR controller unit, on vehicles with code (219) Distronic (DTR)
- 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
- Wheel torque factor, overall gear ratio
ESP 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 control unit
- Engine torque requests, engine intervention when shifting
- ETC limp-home mode
- Starter enable 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
Central gateway control unit
- Diagnosis