Clockspring Assembly / Spiral Cable: Testing and Inspection

Test and detonation current is supplied to the driver airbag via a coil spring (contact roller) fitted between the steering wheel and steering column assembly. The coil spring also supplies current for operation of the horn and audio system via two separate leads. The coil spring consists of two parts, one fixed and one moving. A spiral plastic tape with four embedded leads is fitted between the fixed and moving parts.




The moving part of the coil spring can be rotated about 5 turns, i.e. 2.5 turns in either direction from the centre position. If this is exceeded, the spiral tape will break and put the Supplementary Restraint System out of service.




This is detected by the control module and the airbag warning lamp will light up.