Clockspring Assembly / Spiral Cable: Description and Operation

Contact Roller




To distribute test and detonating current to the steering wheel airbag, there is a contact roller between the steering wheel and the steering wheel bracket. The contact roller also distributes current to the horn through two separate leads..

The contact roller consists of a fixed and a moving part. Between the fixed and the moving parts is a coiled plastic strip with four conductors molded into it.

The moving part of the contact roller can be rotated approx. 5 turns, that is to say approx. 2.5 turns each way from the middle position. If this is exceeded, the coiled strip will break and the SRS is rendered unserviceable. This is detected in the control module and the SRS lamp lights.