Automatic transmission (AT), function - GF27.10-P-0001AHX

TRANSMISSION 722.930 up to 5/31/11, 722.931 as of 6/1/11 in MODEL 212.0/2 

Automatic transmission (AT), general 

Transmission 722.930/931 is an electronically controlled automatic transmission with 7 forward gears and 2 reverse gears. The gear ratios for the gear ranges are achieved by planetary gear sets. All the transmission functions and components for this transmission are combined in one assembly module.

Integration of the fully integrated transmission control controller unit (Y3/8) in the transmission minimizes the number of interfaces to the wiring harness. This improves the shift quality, increases service life and reliability, and also lowers maintenance costs.

Service life can be increased, fuel consumption reduced, gearshift comfort improved and maintenance intervals revised by using optimized transmission components and a new automatic transmission fluid and by reducing working pressure and implementing software modifications.

As of model year 2013/AEJ12 the fully integrated transmission control 4 (VGS4-0) will enter service.

The advantages resulting from this will be:

• Improvement of electromagnetic compatibility (EMC problems)
• Faster current control as well as the compensation of on-board electrical system fluctuations, which leads to increased shift quality
• A more exact determination of shifting-relevant measurement values as well as a faster evaluation of the determined values

The ECO start/stop function will enter into service as of model year AJ11 (1.6.2011) with the transmission 722.931 launch.

The transmission can be subdivided into the following assemblies:

• Wet clutch with torsional damper
• Oil pump for producing the necessary oil pressure and for safe lubrication of actuators and bearing points
• Oil cooling system for optimized short-term heat dissipation
• Transmission housing with mechanical transmission components (planetary gear sets, parking lock, multidisk clutches and multidisk brakes) and fully integrated transmission control controller unit
• Electrical transmission oil pump (M42) (with code (B03) ECO start/stop function) for generating required oil pressure and for reliable lubrication of the actuators and bearing points at engine OFF

Data is exchanged with the following control units via the drive train CAN (CAN C):

• Transmission mode control unit (N145)
• ME-SFI [ME] control unit (N3/10)
• DIRECT SELECT INTERFACE (N150)
• Intelligent servo module for DIRECT SELECT (A80)
• Transmission oil auxiliary pump control unit (N89) (with code (B03) ECO start/stop function)

Valid for vehicles up to facelift 13 

Data is exchanged with the following control units via the ME-SFI [ME] control unit and the chassis CAN (CAN E):

• Instrument cluster (A1)
• Front SAM control unit with fuse and relay module (N10/1)
• Premium Electronic Stability Program control unit (N30/7)
• AIRmatic control unit (N51/3) with code (489) AIRmatic (air suspension with continuous adjustment damping) and code (488) Steel/air suspension
• Electronic ignition lock control unit (N73)
• Steering column tube module control unit (N80)
• Transmission mode control unit

As of facelift 13 the current chassis CAN will be replaced by the chassis CAN 1 (CAN E1). An additional chassis CAN 2 (CAN E2) is used between the instrument cluster and the front SAM control unit with fuse and relay module.

The ME-SFI [ME] control unit is the interface between the drive train CAN and the chassis CAN 1. The interface between the chassis CAN 1 and the chassis CAN 2 forms the front SAM control unit with fuse and relay module.

Further subfunctions are described in separate documents:

• Transmission control, function 
• Key-P function 
• Emergency-P function 
• Shift operation, function 
• Power transmission, function