Clockspring Assembly / Spiral Cable: Description and Operation

Steering Column Switch Center (SZL)

All the components on the steering wheel are controlled by the steering column switch center unit (SZL).The SZL is divided into two electronic modules. One is located in the steering wheel and the other is attached to the steering column. Both units are connected by means of spiral spring.

The SZL contains no ISIS sensors and is responsible for deploying the drivers airbag.




The SZL is integrated in the steering column electronics and linked to the SIM via the byteflight. The power supply of the SZL is also from the SIM and it is buffered by the memory backup capacitor.

In addition, there is a KL 30 for the supply of circuit elements not relevant to safety (e.g. steering wheel heating) and a KL 15 "ON" from the CAS for redundancy.




In sleep mode of the byteflight, the power supply of the SZL is deactivated by the SIM. The watchdog function is run by the SIM.