Is the coil spring a wear part?
Is the spiral cable a wear part?
Yes, the spiral cable (also called slip ring or airbag contact unit) is a wear part. Due to constant mechanical stress with every steering movement, the internal flat ribbon cable wears over time. The result: airbag warning light illuminates, horn and steering wheel buttons no longer function.
The spiral cable sits between the fixed steering column and the rotating steering wheel. It provides the electrical connection to the driver's airbag, horn, and multifunction buttons on the steering wheel. Since it must move with every steering movement, it is subject to high mechanical stress – unlike many other electronic components in the vehicle.
Why does the spiral cable wear out?
The spiral cable contains a thin flat ribbon cable in a housing that winds and unwinds with every steering movement. After thousands of steering movements, this cable can break, contacts can corrode, or insulation can be damaged.
| Wear cause | Description | Effect |
|---|---|---|
| Mechanical wear | Constant winding and unwinding of the flat ribbon cable | Cable breakage, contact interruption |
| Moisture | Condensation or water ingress | Corrosion of contact surfaces |
| Vibrations | Vehicle vibrations on poor roads | Material fatigue |
| Improper installation | Spiral cable not installed in center position | Premature cable tear from over-rotation |
| Aging | Plastic and insulation become brittle | Brittle material, short circuit possible |
How long does a spiral cable last?
A spiral cable typically lasts 100,000 to 200,000 kilometers or 8-15 years. Actual lifespan depends heavily on driving habits: frequent maneuvering and many steering movements (city traffic) significantly accelerate wear compared to long highway driving.
| Driving profile | Expected lifespan | Reason |
|---|---|---|
| Predominantly city traffic | 80,000 – 150,000 km | Many steering movements, frequent maneuvering |
| Mixed (city/highway) | 120,000 – 180,000 km | Average stress |
| Predominantly highway | 150,000 – 250,000 km | Few steering movements, straight course |
Manufacturers do not provide an official lifespan for the spiral cable – it is considered "lifetime-rated". However, practice shows that many spiral cables fail well before the vehicle's end of life, especially in vehicles with high mileage or frequent short-distance use.
How do I recognize a defective spiral cable?
Typical symptoms of a defective spiral cable are: airbag warning light illuminates continuously, horn does not function, steering wheel buttons do not respond, and cruise control cannot be activated. Sometimes grinding or rattling noises occur when steering.
| Symptom | Affected function | Safety-relevant? |
|---|---|---|
| Airbag warning light illuminates | Driver airbag | Yes – airbag does not function |
| Horn does not function | Signal horn | Yes – mandatory equipment, TÜV-relevant |
| Steering wheel buttons dead | Radio, telephone, onboard computer | No – comfort loss |
| Cruise control failed | Speed control | No – comfort loss |
| Grinding noise when steering | Mechanical defect | Warning signal – imminent total failure |
Important: Safety risk
A defective spiral cable means in most cases that the driver's airbag can no longer deploy. This is a significant safety risk and also grounds for TÜV failure. Repair should therefore not be delayed.
Replacing the spiral cable: What should be noted?
Replacing the spiral cable requires removal of the steering wheel airbag and is therefore subject to explosives regulations. Only qualified workshops with appropriate expertise are permitted to perform this work. Before installation, the new spiral cable must be positioned exactly in the center position.
- Disconnect battery: Disconnect negative terminal, wait at least 10 minutes
- Remove airbag: Carefully remove driver airbag
- Remove steering wheel: Loosen steering wheel bolt, remove steering wheel
- Remove old spiral cable: Disconnect connector, release fastening
- Install new spiral cable: Must be installed in center position
- Install steering wheel: Observe torque specification
- Install airbag: Connect connector securely
- Connect battery: Wait for self-test, warning light must go out
Why is the center position so important?
The spiral cable has a limited rotation range (typically 2.5 to 4 rotations in each direction). If it is not installed in the center position, the cable can tear at full steering lock – the most common cause of premature failure after a workshop visit.
Cost for a new spiral cable
A new spiral cable costs between 25 and 325 euros as a replacement part – depending on the vehicle brand and whether a steering angle sensor is integrated. Workshop labor costs for installation are additional.
| Variant | Price range (replacement part) | Special feature |
|---|---|---|
| Simple spiral cable | 25 – 80 € | Airbag connection only |
| With multifunction | 60 – 150 € | Airbag + steering wheel buttons + horn |
| With steering angle sensor | 150 – 325 € | Airbag + buttons + ESP sensor integrated |
Does Airbag24 repair spiral cables?
No, Airbag24 does not offer spiral cable repair or spiral cable 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 illuminated, the problem is not always the spiral cable – often a defective airbag control unit is the cause.
- Airbag control unit repair: We repair defective airbag control units for all common brands and models
- Seat occupancy mat simulators: Suitable simulators for seat occupancy detection in our shop
- Consultation: Are you unsure whether the control unit or spiral cable is defective? We help you with diagnosis
Frequently asked questions about the spiral cable as a wear part
Here you will find answers to the most important questions about spiral cable wear.
Can you prevent a defective spiral cable?
You cannot directly prevent wear since it results from normal steering movements. However, frequent maneuvering with full steering lock accelerates wear. Gentle steering without lock protects the spiral cable. Moisture in the vehicle interior (e.g., clogged water drains) should be avoided.
Is spiral cable replacement subject to TÜV inspection?
The replacement itself is not a TÜV inspection, but a defective spiral cable causes the airbag warning light – resulting in failure at the main inspection. A non-functioning horn is also a TÜV defect. Both together make timely replacement mandatory.
Can the spiral cable be repaired instead of replaced?
Yes, in many cases a spiral cable can be repaired by a specialized workshop – the broken flat ribbon cable is renewed. This is often cheaper than a new part, especially for variants with integrated steering angle sensor. However, repair should only be performed by experienced shops, as the component is safety-relevant.
Are there vehicles where the spiral cable fails particularly often?
Certain models are known for more frequent spiral cable defects – including some VW/Audi models (B platform), older BMW 3 Series (E46, E90), and various Opel models. For these vehicles, it is worthwhile to act early at the first signs of symptoms (horn sporadic, steering wheel buttons intermittently dead).