Which component is essential for the operation of supplemental restraint system (SRS) or airbag systems?

The clock spring, also known as the spiral cable, is a vital component in the operation of the supplemental restraint system (SRS) or airbag systems. It is designed to maintain an electrical connection between the vehicle’s steering wheel—where the airbag is typically housed—and the vehicle’s main electrical system, allowing for the deployment of the airbag when necessary.

When the airbag system is triggered, the clock spring enables the flow of electrical signals required to activate the airbag, ensuring that the components communicate successfully even when the steering wheel is turned. Without this critical connection, the airbag may fail to deploy in the event of a collision, compromising occupant safety.

While the other components mentioned might play roles in vehicle systems or components, they do not provide the necessary functionality required for the SRS operation. The horn relay, for example, is associated with the vehicle's horn but does not interface with the airbag system. Similarly, an airbag sensor, while important, relies on the clock spring for correct functionality to allow airbag deployment, rather than being a standalone essential component. An SD card is unrelated to the airbag system's operational needs altogether.