Workshop Hints

Workshop Hints

Diagnosis

The following component faults can be detected:




Depending on the fault, the system exhibits one of the reactions listed below:




A 12 Pin Adapter Cable, Special Tool # 90 88 6 372 040 is used in conjunction with the DISplus to adapt the MFK cables when diagnosing the ARS system.









A "dynamic" driver will notice the loss of the steering angle signal and the warning messages will be acknowledged. The warning message will disappear once it has been acknowledged. When the cause of the fault is corrected, the ARS control module will have full capacity.

Depending on how fast a fault is detected, there are two reset opportunities:

- When the ignition is off, all faults which have been corrected will be reset. You must wait until the sleep mode has been activated before switching the ignition back on.
- Faults that occur sporadically and can generally be traced back to CAN bus communication malfunctions, are automatically reset when driving straight ahead or when stationary. In this case, the driver may not be aware of the re-activation when driving or when the car is stationary.

The faults are stored in memory with important additional information. The additional information includes the mileage when the fault occurred, details of whether the fault is present and the frequency of the fault occurance.


NOTE: When there is a Dynamic Drive failure, the DSC can not be deactivated or it it is already deactivated it will not switch back on automatically.


Dynamic Drive Commissioning

The commissioning procedure must be carried out using the DISplus after the hydraulic system was opened or a component was replaced (in particular the lateral acceleration sensor). This procedure is found under Service Functions - Chassis - Dynamic Drive - Start Startup - Test Plan and follow the on screen instructions. The following criteria must be met for matching the lateral acceleration sensor and the two pressure sensor offset values:

- The vehicle must stand level on all four wheels (on the ground).
- The vehicle must be unloaded.
- The engine must be idling at operating temperature.
- The doors must be closed and occupants are not allowed in the vehicle.

NOTE: Stay clear of the moving chassis parts during the commissioning! The ground and side to side clearance must not be limited or obstructed and the doors must be closed. The arms of the lift hoist must not be situated underneath the vehicle. Vehicle will not be able to be driven (transmission will remain in "Park" during this procedure).

The commissioning is performed in five steps that are automatically carried out during the procedure:







Dynamic Drive Bleeding

After all work on the Dynamic Drive and the steering system in which hydraulic lines have been opened, the steering system must be bled and initial operation of the Dynamic Drive (commissioning) must be performed with the DISplus.

Procedure:

1. Check fluid level in the powersteering reservoir; if necessary, top up to the "MAX" level while the engine is stopped.
2. Start the engine. Turn the steering wheel left and right to the full lock twice.
3. Check the fluid level with the engine stopped; if necessary, top up to the "MAX" level.
4. Start the engine, connect vehicle to the DISplus.
5. Start the Commissioning procedure which is found under Service Functions - Chassis - Dynamic Drive - Start Startup - Test Plan and follow the on screen instructions.


NOTE: Refer to the Repair Instructions for details on the Dynamic Drive bleeding procedure.