Steering-Angle Sensor

Steering-Angle Sensor


General
As calculation basis for the various functions of the DSC, the steering column switching cluster (SZL) picks up the steering angle and steering wheel turn information, among other things.

Operating principle
The steering angle indicates the angle position of the steering wheel. A steering angle of ±180° is picked up. The signal from the steering angle sensor is repeated every 360°. The steering wheel turns are counted via these signal repetitions. The SZL is supplied permanently via terminal 30. This means that the steering wheel movements are also picked up with ignition OFF. After a power interruption, the neutral position of the steering wheel is retained. However, the steering wheel turn is lost. A calculation model re-determines the current steering wheel turn while the vehicle is being driven. If this process has not been completed by the time a driving speed of 25 kph has been reached, the DSC warning light is set. Other possibilities to determine the steering wheel position after power interruption: Steering from limit position to limit position, running the service function "Adjust Steering Angle"

Encoding (as of 12/04)
The steering angle sensor requires model-specific data for its internal calculations. This data is transferred to the SZL on encoding the DSC control unit. The steering angle sensor can only be adjusted after this encoding.

Adjustment
During adjustment, the current steering wheel position is stored permanently as the straight-ahead position of the steering wheel in the SZL. For this reason, during adjustment the front wheels and the steering wheel must be placed in an exact straight-ahead position. In addition, the serial number of the SZL and the vehicle identification number are stored in the DSC (assignment of DSC to SZL and vehicle). After successful calibration, the fault memory of the steering angle sensor is automatically deleted.
Adjustment must always be carried out after the following operations:
- Replacement of the steering column switch cluster
- Encoding the steering column switch cluster
- Replacement of the DSC control unit
- Adjustment procedure on the steering angle geometry
- Any work on the steering or front axle