GF27.10-P-0001NTX Automatic Transmission (AT), Function

GF27.10-P-0001NTX Automatic transmission (AT), function
- TRANSMISSION 722.9

Component Identification:

General information
Transmission 722.9 is an electronically controlled automatic transmission with 7 forward gears and 2 reverse gears. All the transmission functions and transmission components are combined in one assembly module. Integrating the electrohydraulic controller unit (21) in transmission minimizes the number of interfaces to the wiring harness. The electrohydraulic controller unit (21) is mounted at the bottom of the transmission housing. It is permanently flushed with transmission oil for cooling.

Transmission 722.9 can be roughly divided into the following component groups:
^ Torque converter with torsional damper and torque converter lockup clutch (16)
^ Oil pump (6) for producing the necessary oil pressure and for lubrication of the actuators and bearing points
^ Light alloy transmission housing with mechanical transmission components and electrohydraulic controller unit (21)
^ Mechanical transmission components, consisting of a Ravigneaux gear set (9), front single planetary gear set (12a), rear single planetary gear set (12b) and a park pawl
^ Multidisk clutch K1 (8), multidisk clutch K2 (11), multidisk clutch K3 (14), multidisk brake B1 (7), multidisk brake B2 (15), multidisk brake B3 (10) and multidisk brake BR (13). Single-sided disks are used on the multidisk clutches (8, 11, 14), multidisk brake B1 (7) and multidisk brake B3 (10). On this type of disk the friction lining is only applied on one side. This improves heat distribution in the disk pack and enables a more compact disk pack design while at the same time increasing load-bearing capacity and reducing the mass. Lamella coated on both sides continue to be used for the B2 multi-disk brake (15) and BR multi-disk brake (13).
^ Electrohydraulic controller unit (21), consisting of the electric controller unit (VGS), the valve body and the valve housing

The following information are taken into account when shifting the drive positions:
^ Vehicle speed
^ Vehicle load condition
^ Driving resistance
^ Position and actuation speed of accelerator pedal sensor
^ Position of selector lever and engaged gear a Position of the transmission mode switch
^ Oil temperature and other information about the status of the transmission
^ Additional signals available via CAN-C (CAN-C)

Data exchange with the following control units takes place via CAN-C (CAN-C):
^ Instrument cluster (A1)
^ DTR controller unit (A89) (with code (219) Distronic (DTR))
^ CDI control unit (with diesel engine)
^ ME-SFI [ME] control unit (N3/10) (with gasoline engine)
^ Electronic selector lever module control unit (N15/5)
^ ESP control unit (N47-5)
^ EIS [EZS] control unit (N73)
^ Steering column module (N80)
^ Central gateway control unit (N93)
^ Fully integrated transmission control (VGS) control unit (Y3/8n4)

This involves the processing of the following data from other systems:

DTR controller unit (A89)
^ Shift line displacement, brake the vehicle, the fully integrated transmission control (VGS) shifts down earlier
^ Active downshift, brake the vehicle, fully integrated transmission control shifts down earlier

CDI control unit
^ Shift line displacement, aids engine warm-up
^ Start-off in 1st gear, aids engine warm-up
^ Specified gear, lower/upper limit, aids engine warm-up
^ Shift line displacement dependent on load condition of diesel particulate filter (DPF) (with code (474) particulate filter), a heavily loaded DPF results in slightly lower upshift speed for full-load and kick-down upshifts
^ Emergency operation of the common rail diesel injection (CDI), the pedal value is limited to approx. 20 %, the driveability of the vehicle is assured
^ Cruise control controls, a special shifting strategy for cruise control mode is filed in the fully integrated transmission control (VGS) control unit (Y3/8n4)
^ Request for torque converter lockup clutch (16) "OPEN" during heating up phase of engine, increase in engine speed
^ Kickdown
^ Engine coolant temperature, used as substitute value in event of malfunction in transmission oil temperature sensor (VGS)
^ 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 directiona1stability and road adhesion
^ Engine idle specified speed for the actuation of the torque converter lockup clutch (16)
^ Engine-speed limitation function active, adaptations are deactivated in the fully integrated transmission control (VGS) control unit (Y3/8n4)
^ Engine speed, for slip calculation of torque converter lockup clutch (16) and for start of pressure calculation by fully integrated transmission control (VGS) control unit (Y3/8n4)
^ Pedal value
^ Engine torque

ME-SFI [ME] control unit (N3/10)
^ Catalytic converter heating
- Active downshift
- Start-off in 1st gear
- Shift line displacement
- Specified gear lower/upper limit
^ Kickdown
^ 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
^ Cruise control controls, a special shifting strategy for cruise control mode is filed in the fully integrated transmission control (VGS) control unit (Y3/8n4)
^ Engine coolant temperature, used as substitute value in event of malfunction in transmission oil temperature sensor (VGS)
^ Engine oil temperature, shift limitation is canceled
^ Engine idle specified speed for the actuation of the torque converter lockup clutch (16)
^ Requirement torque for Electronic Stability Program (Electronic-Stability-Program) (ESP), torque reduction or torque increase taking into account directiona1stability and road adhesion
^ Request for torque converter lockup clutch (16) "Open" in the heating up phase of the catalytic converter, to increase engine speed
^ Engine torque
^ Pedal value
^ Engine speed, for slip calculation of torque converter lockup clutch (16) and for start of pressure calculation by fully integrated transmission control (VGS) control unit (Y3/8n4)
^ Engine-speed limitation function active, adaptations are deactivated in the fully integrated transmission control (VGS) control unit (Y3/8n4)

Electronic selector lever module control unit (N15/5)
^ Selector lever position
^ Transmission mode switch

ESP control unit (N47-5)
^ Stop lamp switch, change of shift strategy, brake the vehicle, fully integrated transmission control shifts down earlier
^ Wheel speeds and direction of rotation, substitute values in event of malfunction of output speed sensor (VGS)
^ Adjusted braking torque, change of shift strategy, brake the vehicle, fully integrated transmission control shifts down earlier
^ ESP request shift into "N" (neutral), power flow interruption, transmission/rear axle
^ Vehicle lateral acceleration at center of gravity, adaptation of shift strategy, detection of dynamic driving style

EIS control unit (N73)
^ Refrigerant compressor ON
^ circuit 50, influencing fault storage
^ Torque requirement of refrigerant compressor, torque correction

Steering column module (N80)
^ Status of left steering wheel gear shifter and right steering wheel gear shifter (vehicles up to 31.5.06 with code (428) Steering wheel shift buttons)
^ Status of steering wheel gear shifter MINUS and steering wheel gear shifter PLUS (AMG vehicles and vehicles as of 1.6.06 with code (428) Steering wheel shift buttons)

Central gateway control unit (N93)
^ Refrigerant compressor ON
^ circuit 50, influencing fault storage
^ Torque requirement of refrigerant compressor, torque correction

The following information is transmitted to other systems:

Instrument cluster (A1)
^ Selector lever position for gear indicator
^ Mode selection on transmission mode switch for transmission mode display

DTR controller unit (A89)
^ 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

CDI control unit or ME-SFI [ME] control unit (N3/10)
^ Engine torque requests, engine intervention when shifting
^ Emergency-running mode for fully integrated transmission control
^ Starter lockout release in selector lever 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
^ Torque converter lockup clutch (16) status

ESP control unit (N47-5)
^ Wheel torque factor, overall gear ratio
^ 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

EIS control unit (N73)
^ Selector lever position for backup lamp actuation

Central gateway control unit (N93)
^ Selector lever position for backup lamp actuation
^ Diagnosis request