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

GF27.10-P-0001NK 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 electro hydraulic controller unit (21) in transmission minimizes the number of interfaces to the wiring harness. The electro hydraulic 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 electro hydraulic 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).

^ Electro hydraulic 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
^ Position of the transmission mode switch
^ Oil temperature and other information about the status of the transmission
^ Additional information available via CAN-C (CAN-C)

Data exchange with the following control units takes place via CAN-C (CAN-C):
^ Instrument cluster (A1)
^ ME-SFI [ME] control unit (N3/10)
^ Electronic selector lever module control unit (N15/5)
^ ESP and BAS 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:
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
^ kick down

^ Emergency operation of the ME-SFI [ME] gasoline 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) (up to 31.5.05)
^ 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 directional stability and road adhesion
^ Pedal value
^ Engine torque
^ Request for torque converter lockup clutch (16) "Open" in heating up phase of catalytic converter to increase engine speed
^ Engine idle specified speed for the actuation of the torque converter lockup clutch (16)
^ 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 (N16/6)
^ Selector lever position
^ Transmission mode switch

ESP and BAS control unit (N47-6)
^ BAS release switch, change of shift strategy, brake the vehicle, the fully integrated transmission control (VGS) 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 to drive position "N", power flow interruption, transmission/rear axle
^ Vehicle lateral acceleration at center of gravity, adaptation of shift strategy, detection of dynamic driving style
^ Cruise control controls, a special shifting strategy for cruise control mode is filed in the fully integrated transmission control (VGS) control unit (Y3/8n4) (as of 1.6.05)

EIS control unit (N73)
^ Refrigerant compressor ON
^ Circuit 50, influencing fault memory
^ 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 (model 171.473 and vehicles as of 1.6.06 with code (428) Steering wheel shift buttons)

Central gateway control unit (N93)
^ Refrigerant compressor ON
^ Circuit 50
^ Torque requirement of refrigerant compressor, torque correction

The following information is transmitted to other systems: Instrument cluster (A1)
^ Selector lever position for lower multifunction display
^ Status of transmission mode switch for lower multifunction display

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 and BAS control unit (N47-6)
^ 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