Clock Spring

📖 YOUCANIC Automotive Glossary

The clock spring (also called spiral cable, contact reel, or coil spring assembly) is a coiled flat ribbon cable housed in a plastic cassette located between the steering wheel and steering column that maintains continuous electrical connections to steering wheel-mounted components while allowing the steering wheel to rotate freely. The clock spring carries connections for the driver’s airbag, horn, steering wheel audio/phone/cruise control buttons, and on some vehicles, the heated steering wheel. The ribbon cable winds and unwinds as the steering wheel turns, providing uninterrupted electrical continuity through the full steering range (typically 2.5-3.5 turns lock to lock).

Clock spring failure is common and causes the airbag warning light (SRS light) from a driver airbag circuit code, non-functioning horn, and dead steering wheel buttons — all pointing to the steering wheel electrical connections. The clock spring can fail from wear over time or from being broken during steering column work if the wheel is turned with the clock spring disconnected (overextending the ribbon cable). When the SRS light is on due to a clock spring fault, the driver’s airbag will not deploy in a crash. The YOUCANIC UCAN-II reads SRS codes that identify driver airbag or squib circuit faults, pointing to clock spring inspection. After clock spring replacement, the new unit must be centered before installation to prevent cable damage.