Suspension Control ( Automatic - Electronic ): Description and Operation

GF32.32-P-1010RD Component Description For Adaptive Damping System Control Unit
MODEL 172.4
- with CODE (483) ADVANCED AGILITY package





View of model 172.4 from above

N51/5 Adaptive damping system control unit

Location

The adaptive damping system control unit is located in the center of the control unit carrier in the trunk.

Task
The adaptive damping system control unit does the following:
^ Reading in of sensors, pickups and signals
^ Evaluation of input factors
^ Actuating components

Reading in of sensors, pickups and signals
The input factors are read in via the following connections:
^ Direct line
^ Chassis CAN (CAN E)

Direct line
The signals from the following components are read via a direct line:
- Left rear level sensor (B22/7)
- Left front level sensor (B22/8)
- Right front level sensor (B22/9)
- Right rear level sensor (B22/10)
- Left front body acceleration sensor (B24/3)
- Right front body acceleration sensor (B24/4)
- Right rear body acceleration sensor (B24/6)

Chassis CAN
The following signals are read in over the chassis CAN:
- Vehicle speed sent as a substitute value from the instrument cluster (A1)
- Circuit 61 status, kick down status (with transmission 722.9) and drive variant, sent from CDI control unit (N3/9) (with diesel engine) or from the ME-SFI [ME] control unit (N3/10) (with gasoline engine)
- Vehicle dynamics status button (N72/1s23), sent from the front SAM control unit with fuse and relay module (N10/1)
- Wheel speed, rotational speed, lateral and longitudinal acceleration, status of service brake and braking torque, sent from Electronic Stability Program control unit (N30/4)
- Steering angle and steering angle speed, sent by steering column tube module control unit (N80)

Evaluation of input factors
The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Component actuation
The components are actuated via the following lines:
^ Direct line
^ Chassis CAN

Direct line
The following components are actuated via a direct line:
- Left front axle damping valve unit (Y51)
- Right front axle damping valve unit (Y52)
- Left rear axle damping valve unit (Y53)
- Right rear axle damping valve unit (Y54)

Chassis CAN
The following components are actuated via the chassis CAN:
- Light-emitting diode (LED) in vehicle dynamics button sent over instrument panel IN (LIN 1) from front SAM control unit with fuse and relay module

Rotational speed, lateral and longitudinal acceleration
On the ABR Premium system (with code (233) DISTRONIC PLUS) the data of the yaw rate sensor for lateral and longitudinal acceleration (B24/15) are read in by the Electronic Stability Program control unit over the vehicle dynamics CAN (CAN H).
On the ABR Basis system (except code (233) DISTRONIC PLUS) the yaw rate sensor for lateral and longitudinal acceleration is integrated into the ESP control unit, whereby a CAN connection to an external yaw rate sensor for lateral and longitudinal acceleration is no longer required. The data for the rotational speed, lateral and longitudinal acceleration are therefore recorded and evaluated directly by the Electronic Stability Program control unit.