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

GF27.10-P-0001NQ Automatic transmission (AT), function
- Transmission 722.9

Component Identification:

General information
Transmission 722.9 is an electronically controlled automatic transmission with 7 forwards and 2 reverse gears. All transmission functions and transmission components have been combined in an assembly module. Integrating the electrohydraulic controller unit (21) in transmission 722.9 minimizes the number of interfaces to the wiring harness. The electrohydraulic controller unit (21) is installed at the bottom of the transmission housing. It is constantly flushed with transmission oil and cooled as a result.

The transmission 722.9 can be subdivided 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 lubricating the actuators and bearing points
^ Transmission housing made from light metal alloy with mechanical transmission components and electrohydraulic controller unit (21)
^ Mechanical transmission components, consisting of the Ravigneaux gear set (9), the single front planetary gear set (12a), the single rear planetary gear set (12b) and the 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). The friction lining is only coated on one side on this type of lamella. As a result the heat distribution in the clutch pack has been improved and simultaneously compactness has been achieved, the load-carrying capacity having been increased the mass having been reduced. 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 is taken into account when monitoring and shifting:
^ Vehicle speed
^ Load condition of the vehicle
^ Driving resistance
^ Position and operating speed of accelerator pedal
^ Position of selector lever and engaged gear
^ Position of transmission mode switch
^ Oil temperature and other information about the status of the transmission
^ Additional information which is available via CAN C

A data exchange from the following control units takes place via CAN C:
^ Instrument cluster (A1)
^ DTR controller unit (A89) (with code 219 Distronic (DTR))
^ CDI control unit (N3/9) (on diesel engine)
^ ME-SFI [ME] control unit (with gasoline engine)
^ Electronic selector lever module control unit (N15/5)
^ ESP and BAS control unit (N47-5)
^ EZS control unit (N73)
^ Steering column module (N80)
^ Fully integrated transmission control (VGS) control unit (Y3/8n4)

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

DTR controller unit
^ 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 curve offset, aids engine warm-up
^ Specified gear, lower/upper limit, aids engine warm-up
^ Shift line displacement depending on the load condition of the diesel particulate filter (DPF) (with code 474 particulate filter), a heavily laden DPF results in a slightly lower upshift speed during full load and kick down upshifts
^ Start-off in 1st gear, aids engine warm-up
^ Emergency running mode
^ Cruise control controls, a special shifting strategy for cruise control mode is stored in the fully integrated transmission control (VGS) control unit (up to 31.5.05)
^ Engine coolant temperature is used as a substitute value in the event of failure of the transmission oil temperature sensor (VGS)
^ Engine torque
^ 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
^ Request for torque converter lockup clutch (16) "OPEN" during heating up phase of engine, increase in engine speed
^ Engine idle specified speed for the actuation of the torque converter lockup clutch (16)
^ Rpm limitation function active, adaptations in the fully integrated transmission control (VGS) control unit (Y3/8n4) are switched off
^ Engine speed, for slip calculation of the torque converter lockup clutch (16) and for the start of the pressure calculation by the fully integrated transmission control (VGS) control unit
^ kick down

ME-SFI control unit
^ Catalytic converter heating
- Active downshift
- Start-off in 1st gear
- Shift line displacement
- Specified gear lower/upper limit
^ Emergency running mode
^ Engine coolant temperature is used as a substitute value in the event of failure of the transmission oil temperature sensor (VGS)
^ Engine oil temperature, shift limitation is canceled
^ ESP requirement torque, torque reduction or torque increase taking into account directional stability and road adhesion
^ Request for torque converter lockup clutch (16) "OPEN", in the heating-up phase for the catalytic converter, increase engine speed
^ kick down
^ Engine idle specified speed for the actuation of the torque converter lockup clutch (16)
^ Engine speed, for slip calculation of the torque converter lockup clutch (16) and for the start of the pressure calculation by the fully integrated transmission control (VGS) control unit
^ Pedal value
^ Engine torque
^ Rpm limitation function active, adaptations in the fully integrated transmission control (VGS) control unit are switched off

Electronic selector lever module control unit
^ Selector lever position
^ Status of transmission mode switch

ESP and BAS control unit
^ Vehicle lateral acceleration at center of gravity, adaptation of shift strategy, detection of dynamic driving style
^ Adjusted braking torque, change of shift strategy, brake the vehicle, fully integrated transmission control shifts down earlier
^ Wheel speeds and direction of rotation, substitute values in the event of failure of the output rpm sensor (VGS)
^ Cruise control controls, a special shifting strategy for cruise control mode is stored in the fully integrated transmission control (VGS) control unit (as of 1.6.05)
^ ESP request shift into "N" (neutral), power flow interruption, transmission/rear axle
^ BAS release switch (A7/7s1), change of shift strategy, brake the vehicle, fully integrated transmission control shifts down earlier

EIS [EZS] control unit
^ Refrigerant compressor (A9) ON
^ Circuit 50, influencing fault memory
^ Torque requirement of refrigerant compressor

Steering column module
^ Status of left steering wheel gear shifter (S110/2) and right steering wheel gear shifter (S111/2) (up to 31.5.06 with code 428 steering wheel shift buttons)
^ Status of steering wheel gear shifter MINUS (S110/1) and steering wheel gear shifter PLUS (S111/1) (AMG vehicles and vehicles as of 1.6.06 with code 428 steering wheel shift buttons)

The following information is sent to other systems:

DTR controller unit
^ Transmission variant, recognition of basic variants, difference in gear ratios
^ Actual gear engaged/target gear, engaged gear, gear to be shifted can be shown via STAR DIAGNOSIS
^ Wheel torque factor, overall gear ratio

CDI control unit
^ 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, gear engaged, gear to be shifted, can be shown via STAR DIAGNOSIS
^ Torque converter lockup clutch (16) status
^ Engine torque requests, engine intervention when shifting
^ Emergency-running mode for fully integrated transmission control

ME-SFI control unit
^ Transmission variant, recognition of basic variants, difference in gear ratios
^ Actual gear engaged/target gear, gear engaged, gear to be shifted, can be shown via STAR DIAGNOSIS
^ Torque converter lockup clutch (16) status

ESP and BAS control unit
^ Wheel torque factor, overall gear ratio
^ Transmission variant, recognition of basic variants, difference in gear ratios
^ Actual gear engaged/target gear, gear engaged, gear to be shifted, can be shown via STAR DIAGNOSIS

EIS [EZS] control unit
^ Selector lever position for reverse lamp actuation
^ Diagnosis request

Instrument cluster
^ Selector lever position for the gear indicator
^ Mode selection at transmission mode switch