Adaptive Damping System (ADS), Function - GF32.32-P-0002RF

Model 205 

as of model year 2019 

with code 459 (DYNAMIC BODY CONTROL suspension with adjustment damping) 

Model 205 

up to model year 2016 

with code 492 (AMG performance suspension) 

with code B59 (AGILITY SELECT) 

Model 205 

with code 485 (AGILITY CONTROL suspension with comfort tuning) 

Model 205 

with code 488 (Steel/air suspension) 

Model 205 

with code 677 (AGILITY CONTROL suspension) 

Courtesy of MERCEDES-BENZ USA

Block diagram 

Function requirements, general 

• Circuit 15 ON

The electronic ignition lock control unit provides the circuit 15 status on chassis FlexRay.

Adaptive damping system (ADS), general 

ADS is a combination of steel suspension with continuous damper adjustment, whereby the dampening is adapted on a wheel-specific basis to match the road surface condition and the driving style. The previously set damping stage is active when the ignition is switched on.

The ADS system is made up of the following component functions:

• Record function sequence for driving condition 
• Select function sequence for damping mode 
• Function sequence, shock absorber adjustment 

Record additional function requirements for driving condition 

• Drive train operational

Record function sequence for driving condition 

The driving condition is defined through the following variables:

• Vehicle level and damping speed
• Vehicle body acceleration (chassis movement)
• Vehicle longitudinal and lateral acceleration

The vehicle level and damping speed are recorded by the following sensors:

• Left front level sensor
• Right front level sensor
• Left rear level sensor
• Right rear level sensor

The vehicle body acceleration is recorded by the following sensors:

• Left front body lateral acceleration sensor
• Right front body lateral acceleration sensor
• Left rear body lateral acceleration sensor

The adaptive damping system control unit reads in the signals of the listed sensors directly.

The data for the yaw rate and the lateral and longitudinal acceleration is recorded by the supplemental restraint system control unit and transmitted to the Electronic Stability Program control unit via the vehicle dynamics CAN for evaluation. The data for yaw rate, lateral and longitudinal acceleration is made available to the adaptive damping system control unit on the chassis FlexRay. The Electronic Stability Program control unit also transmits information about the wheel speeds, the brake status and the braking torque via chassis FlexRay to the adaptive damping system control unit. This information is used for computation of the vehicle speed and the probable chassis movement.

The adaptive damping system control unit also receives the following information via chassis FlexRay, which is used to calculate the ideal damping stage or damping force at each shock absorber:

• Body variant from the front SAM control unit (over the telematics CAN, head unit, user interface CAN and the electronic ignition lock control unit)
• Steering wheel angle and steering wheel velocity, recorded by the steering wheel angle sensor, provided by the steering column tube module control unit
• Kickdown request (sent by fully integrated transmission control unit to CDI control unit (for diesel engine) or ME-SFI [ME] control unit (for gasoline engine) over the drive CAN) and the drive type from the CDI control unit (for diesel engine) or from the ME-SFI [ME] control unit (for gasoline engine), over the engine CAN to the drivetrain control unit interface
• Vehicle speed as substitute value from instrument cluster

The wheel speeds are determined by the left front axle rpm sensor, right front axle rpm sensor, left rear axle rpm sensor and right rear axle rpm sensor and directly read in by the Electronic Stability Program control unit.

Select function sequence for damping mode 

You can choose between sporty or comfortable suspension tuning in the menu by operating the DYNAMIC SELECT switch in the left lower control panel.

Operation of the DYNAMIC SELECT switch is read in by the left lower control panel. The left lower control panel sends the signal over the lower control panel LIN, the Audio/COMAND control panel, the head unit, the user interface CAN, the electronic ignition lock control unit and the chassis FlexRay to the Electronic Stability Program control unit. The Electronic Stability Program control unit transmits the information via chassis FlexRay to the adaptive damping system control unit. The adaptive damping system control unit receives the corresponding request and generates the required actuation signals for the actuators. The driver can also choose between sporty or comfortable suspension tuning using the Comfort/Sport button. The operation of the Comfort/Sport button is read in by the left lower control panel. The left lower control panel transmits the signal via lower control panel LIN, Audio/COMAND control panel, head unit, user interface CAN, electronic ignition lock control unit and chassis FlexRay to the adaptive damping system control unit.

Additional function requirements for shock absorber adjustment 

• Drivetrain operational sent (from CDI control unit (for diesel engine) or the ME-SFI [ME] control unit (for gasoline engine) to suspension FlexRay)

Function sequence, shock absorber adjustment 

The input signals are used by the adaptive damping system control unit to determine each ideal damping stage and directly actuates the following components accordingly:

• Left front axle damping valve unit
• Right front axle damping valve unit
• Left rear axle damping valve unit
• Right rear axle damping valve unit

Implementation of the continuous damping adjustment is carried out using single-tube gas-filled shock absorbers. The damping valve units are located at the bottom side on the single-tube gas-filled shock absorbers.

One check valve each is integrated in the main piston and in the bottom valve of the single-tube gas-filled shock absorbers. These check valves ensure that an identical flow direction is given through the damping valve unit, both in the rebound and the compression stages. This design enables the damping valve unit of a shock absorber to consist of a single regulated proportional valve only.

The flow area in the damping valve unit can be continuously adjusted through actuation of this proportional valve. More or less oil can flow through the damping valve unit to match the set cross section. The damping behavior then becomes correspondingly softer or harder.

The fault codes are stored in the fault memory. These can be read out using Mercedes' XENTRY Diagnostics. The diagnosis status is received by the diagnostics connection (X11/4) from the adaptive damping system control unit over the suspension FlexRay, electronic ignition lock control unit and the diagnostics CAN (CAN D).

	Electrical function schematic for adaptive damping system (ADS)		PE32.32-P-2051-97FBA
	Overview of system components for adaptive damping system (ADS) component description		GF32.32-P-9998RF