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All-Wheel Drive Control Unit, Component Description - GF28.19-P-3211AVO

Model 257.361, 290 

up to model year 2021 

Fig 1: All-Wheel Drive Control Unit Component Location - Model 257.361 Up To Model Year 2021
G14549194Courtesy of MERCEDES-BENZ USA

Shown on vehicle with transfer case 

Location 

The all-wheel drive control unit is attached to the lower part of the transfer case.

Task 

The all-wheel drive control unit actuates the all-wheel drive actuator (N45/1) integrated in the all-wheel drive control unit, in order to enable variable torque distribution. The all-wheel drive actuator then controls the multidisk clutch in the transfer case.

The torque to the front axle is variably regulated through this multidisk clutch. If the multidisk clutch is open, the entire drive torque will be delivered to the rear axle. When the multidisk clutch is closed, up to 50 % of the drive torque will be applied to the front axle. Control here is performed automatically and cannot be influenced by the driver.

IMPORTANT Messages in the instrument cluster (A1)

If case of faults in the system, messages to this effect will be displayed in the instrument cluster.

Control module programming 

The all-wheel drive control unit is programmable, i.e. the complete software of the control unit can be exchanged (replaced). It is also possible to exchange the data separately. The software required for control unit programming is stored on the diagnosis software DVD.

Suspension FlexRay (Flex E) 

The all-wheel drive control unit is connected through the chassis FlexRay to the vehicle's network group and exchanges data with the other control units.

Input factors over a direct line Initial parameters over a direct line Supplemental information
Circuit 31 - -
Circuit 30 - -
Terminal 15 - -
Transmission oil temperature sensor signal (B91) - Only model 290 with engine 177.9
- All-wheel drive actuator (N45/1) Integrated in the all-wheel drive control unit (N45)

Chassis FlexRay input/output signals 

Input and output factors for the following control units are sent or received by the all-wheel drive control unit via the chassis FlexRay:

Input factors over suspension FlexRay (Flex E) Output factors over suspension FlexRay (Flex E) Supplemental information
Electronic Stability Program control unit (N30/4) Electronic Stability Program control unit (N30/4) -
Powertrain control unit (N127) Powertrain control unit (N127) -
Electronic ignition lock control unit (N73) Electronic ignition lock control unit (N73) -
Drive Unit control unit (N145/1) Drive Unit control unit (N145/1) -
Electrical power steering control unit (N68) - -
- Instrument cluster (A1) Via the electronic ignition lock control unit (N73) and user interface CAN (CAN HMI)
- ME-SFI [ME] control unit (N3/10) Via the powertrain control unit (N127) and the drive CAN (CAN C1)
- Control unit for electric controller unit of fully integrated transmission control (Y3/8n4) Via the powertrain control unit (N127) and the drive CAN (CAN C1)
  Wiring diagram of all-wheel drive control unit   PE28.19-P-2103-97XBA