Where is the coil spring located?
Where is the clock spring located in the car?
The clock spring is located between the steering wheel and the steering column on the driver's side. It is housed in a closed casing directly behind the steering wheel and becomes visible once the driver's airbag is removed. The clock spring provides the electrical connection between the rotating steering wheel and the fixed wiring harness.
Without the clock spring, no electrical signals could be transmitted from the steering wheel to the vehicle. It is an essential component that works with every steering movement – and for this reason, it is subject to natural wear and tear.
How is the clock spring constructed?
The clock spring consists of a special conductor foil (flat ribbon cable) in a closed plastic housing. With each steering movement, this foil is wound or unwound. This keeps the electrical connection intact with every steering input – without mechanical tension and with constant resistance.
| Component | Function | Position |
|---|---|---|
| Conductor foil / flat ribbon cable | Transmits electrical signals | Wound inside the housing |
| Plastic housing | Protects the foil from damage | Between steering wheel and steering column |
| Upper connection | Connection to steering wheel (airbag, horn, etc.) | Steering wheel side |
| Lower connection | Connection to wiring harness / control unit | Steering column side |
The principle is simple: instead of a rigid cable that would break during steering, the flat ribbon cable rolls up and down in a controlled manner with each rotation. The clock spring is designed for a specific number of rotations – typically about 3.5 rotations in each direction from the center position.
What signals does the clock spring transmit?
The clock spring transmits all electrical signals between the steering wheel and vehicle: airbag firing line, horn, steering wheel buttons for radio and telephone, multifunction buttons, steering wheel heating, and on newer vehicles, data for driver assistance systems.
| Signal | Function | Safety relevance |
|---|---|---|
| Airbag firing line | Triggering the driver's airbag | Very high |
| Horn | Activating the signal horn | High (road traffic regulations relevant) |
| Multifunction buttons | Operating radio, telephone, cruise control | Low |
| Steering wheel heating | Power supply to heating wires | None |
| Driver assistance | Data for lane-keeping assistant, etc. | Medium |
Difference between clock spring and slip ring
Older vehicles use a simple slip ring that only transmits the horn signal. The modern clock spring has significantly more conductor tracks and additionally transmits airbag, steering wheel buttons, and heating. Both components are located in the same place – between the steering wheel and steering column.
How do you recognize a defective clock spring?
A defective clock spring is indicated by the airbag warning light, a non-functioning horn, failed steering wheel buttons, or scraping noises during steering. Often multiple functions fail simultaneously, as they all run through the same clock spring.
| Symptom | Affected signal | TÜV relevant |
|---|---|---|
| Airbag warning light illuminates | Airbag firing line interrupted | Yes – major defect |
| Horn does not function | Horn signal interrupted | Yes – defect |
| Steering wheel buttons non-functional | Multifunction lines defective | No |
| Steering wheel heating failed | Heating circuit interrupted | No |
| Scraping/grinding noises during steering | Mechanical defect in housing | Indirectly |
How is the clock spring replaced?
Replacement requires removal of the steering wheel and driver's airbag. The new clock spring must be installed exactly in the center position – otherwise it will tear during a full steering input. Work on the airbag system may only be performed by qualified personnel.
- Disconnect battery: Wait at least 10 minutes (capacitor discharge)
- Remove airbag: Loosen fastening screws on steering wheel
- Remove steering wheel: Loosen center screw, mark steering wheel
- Remove old clock spring: Disconnect connector, open fasteners
- Center new clock spring: Turn to stop, then back 3.5 rotations
- Assembly: Install steering wheel, mount airbag
- Function test: Connect battery, warning light must go out
Important: The center position of the clock spring is critical. If installed incorrectly, the conductor foil will tear during full steering input – the result is another defect and possibly a non-functioning airbag.
What does clock spring replacement cost?
A new clock spring costs between 25 and 325 euros depending on the vehicle model. Simple versions (airbag connection only) are at the lower end, variants with multifunction buttons and integrated steering angle sensor at the upper end. Labor costs for removal and installation are approximately 100 to 200 euros.
Does Airbag24 repair clock springs?
No, Airbag24 does not offer clock spring repair or clock spring sales. Our specialty is the repair of airbag control units and the sale of simulators for seat occupancy mats. If your airbag warning light is on, however, the problem is not always the clock spring – often a defective airbag control unit is the cause.
- Airbag control unit repair: We repair defective airbag control units for all common makes and models
- Seat occupancy mat simulators: Suitable simulators for seat occupancy detection in our shop
- Consultation: Are you unsure whether the control unit or clock spring is defective? We help you with diagnosis
Frequently asked questions about clock spring position
Here you will find answers to the most important questions about the installation location of the clock spring.
Can I see the clock spring myself?
In the installed state, the clock spring is not visible. It only becomes accessible when the driver's airbag and steering wheel are removed. From the outside, there is no way to assess the condition of the clock spring – diagnosis is performed via the fault memory.
Does every car have a clock spring?
Yes, every vehicle with a driver's airbag has a clock spring or slip ring. In modern vehicles with a multifunction steering wheel, steering wheel heating, and airbag, a clock spring is always installed. Older vehicles without an airbag only have a simple slip ring for the horn.
Can you drive with a defective clock spring?
The vehicle is drivable, but the driver's airbag does not function and the horn often fails as well. Both are safety-relevant and TÜV-relevant defects. The defect should be corrected immediately.
Why does the clock spring break?
The conductor foil inside breaks due to years of mechanical stress – every steering movement puts strain on the material. Particularly frequent steering to the limit accelerates wear. A clock spring installed with incorrect centering can also tear immediately.