ADS Control Module

ADS Control Module






The Adaptive Damping System (ADS) control module is broken down into the following functions:
- Signal Conditioning
- Function Logic Section
- Safety Circuit

Signal Conditioning
- The following input signals are processed by the function logic section for calculation or information purposes:

- Calculation Of Vertical Body Accelerations
- Body acceleration sensors signal

- Calculation Of Vehicle Speed
- Wheel speed signal
- Speed status signal

- Calculation Of Longitudinal And Lateral Acceleration
- Wheel speed signal
- Steering angle sensor signal

- Calculation Of Vehicle Level
- Level sensors signal

- Information Signals (Operation)
- Stop lamp switch signal
- Comfort/Sport switch signal
- Level control switch signal

Function Logic Section
- The conditioned input signals are processed in the logic section and converted into output signals.

- Body Acceleration Sensors Signal (B24/3, B24/4, B24/6):
- The following are determined by the Electronic Traction System (ETS), Acceleration Slip Regulation (ASR) or Electronic Stability Program (ESP) control module by means of the wheel speed signal

- Wheel Speed Signal:
- The vertical acceleration of the vehicle is calculated from the signals from the body acceleration sensors.
- Vehicle speed
- Longitudinal acceleration

- Speed Status Signal:
- This signal comes from the ETS, ASR or ESP control module and is used as a plausibility check of the wheel speed signal. A distinction is made between a vehicle which is driving and one which is stationary. A defective wheel speed signal is also recognized.

- Steering Angle Sensor (N49) Signal:
- The lateral acceleration of the vehicle is calculated via the steering angle sensor signal and the wheel speed signal.

- Level Sensors Signal (B22/2, B22/3):
- The level sensors of the front and rear axle each provide two signals which determine the distance between the center of the wheel and the body (mean value from the right and left wheel)

- Stop Lamp Switch (S9/1) Signal:
- When the brake is operated a signal is recognized by the ADS logic section and the damping set to "sport" on all wheels. As a result the pitch motion of the vehicle can be reduced during braking.

- Comfort/Sport Switch (S45/1 ) Signal:
- The signal from the comfort/sport switch provides information on the selection between a comfort-orientated and a sport map. The driver's requirement remains stored until it is revised again by the driver (even with ignition OFF)

- Level Adjustment Switch (S77/1) Signal:
- The control module recognizes the driver's requirement for vehicle level by means of the signal from the level adjustment switch:
- Normal level
- Higher level stage 1
- Higher level stage 2
- Lock-out position

- ADS II
- The control module determines the optimum damping stage in each case from the vertical body accelerations determined and the longitudinal and lateral acceleration of the vehicle and the vehicle speed.
- The four different damping force stages can be adjusted at each wheel by actuating the damper valves which are assigned to the wheels.

- Level Control And Adjustment
- The control module adjusts the correct vehicle level from the driver's required setting on the level adjustment switch and from the vehicle speed via the respective level valves depending on the load.

Safety Circuit
- The ADS control module monitors all the important components of the system after switching on and during operation. The task of the safety circuit is to recognize defective signals from sensors, faults in the control module and in the electrical wiring system. If a fault if recognized the system is then switched off and this is displayed to the driver by the ADS malfunction indicator lamp (A1e27) lighting up. The damper valves are no longer actuated and are in the sport damping stage (safe driving stage)
- A fault code is also stored in the control module. Depending on the fault the level control is only partially switched off.
- The safety circuit also constantly monitors battery voltage. If the voltage of 10.5 V is not achieved or 17.5 V is exceeded, the system is also switched off until the voltage is within the specified range again.