Clocksprings and Airbag System Compliance

The clockspring is one of the least understood components in an aftermarket steering wheel purchase. It is also one of the most consequential. This page explains what a clockspring does, why it is specific to your vehicle variant, what causes one to fail, and how the PVS steering wheel kit is designed so that yours never comes out of the car.

What is a Clockspring

A clockspring (also called a spiral cable or clock spring) is a rotary electrical connector mounted inside the steering column, between the fixed wiring of the vehicle and the rotating steering wheel. It maintains a continuous electrical connection regardless of steering wheel position, allowing the following systems to operate through the full range of wheel rotation:

• Driver airbag (SRS system)
• Horn
• Cruise control buttons
• Audio and multimedia controls
• Phone and voice controls
• Lane keep assist and other driver assist inputs (where fitted)

The clockspring is a consumable safety component. It is vehicle-specific. Its electrical paths, connector pinout, loop resistance, and physical dimensions differ between vehicle variants, model years, and steering wheel configurations.

Why the Clockspring is Specific to Your Vehicle

On a Toyota LandCruiser 70 Series, the factory clockspring is engineered for that exact variant. Its electrical paths, connector pinout, loop resistance and physical dimensions are matched to the vehicle it was built for.

This matters because a vehicle fitted with steering wheel controls needs a clockspring with additional wiring paths for those functions. A vehicle without those controls uses a different clockspring entirely. The standard 70 Series clockspring makes no provision for steering wheel controls, which is why adding buttons to one has traditionally meant replacing it.

A steering wheel kit that supplies a replacement clockspring is asking you to swap a component matched to your vehicle for one that must be verified against it. That verification is the buyer's problem, not the seller's, and it is not something you can check by looking at the part.

What Causes a Clockspring to Fail

A clockspring is a consumable component. The internal ribbon cable endures constant rotation and vibration every time the wheel is turned. Commonly cited causes of failure include:

• Repeated steering over many years of driving
• Faulty installation, or incorrect centring after a repair or a steering wheel change
• Airbag deployment, which can damage the clockspring
• Exposure to heat, dust or moisture

Note the second one. Installation is itself a cause of failure. Fitting a clockspring is not a bolt-on job: it means disabling the SRS, removing the steering wheel, and centring the new unit correctly. Get the centring wrong and the ribbon inside can be torn by normal steering travel.

When a clockspring fails, the consequences range from inconvenient to serious. Steering wheel controls and the horn can stop working. An SRS or airbag warning light may appear on the dash. Fitting a clockspring that is not correct for the vehicle can also raise other dash warnings: one Australian steering wheel seller notes on its own product page that where the wrong clockspring is fitted, "the vehicle may show traction control or stability control warning lights".

Most seriously, the clockspring carries the circuit that connects the driver's airbag. If that circuit is broken, the airbag may not deploy in a collision, and there is often no outward sign that this has happened without an SRS diagnostic scan.

Compliance: What Actually Applies

The Australian Design Rules are national standards that apply to a vehicle when it is first manufactured or imported, under the Road Vehicle Standards Act 2018. They do not, by themselves, govern what an owner does to a vehicle afterwards.

What governs a modification is in-service state law. In New South Wales, the Road Transport (Vehicle Registration) Regulation 2017 requires a vehicle to be constructed to comply with the applicable Australian Design Rules, and to continue to comply with them in order to remain registered for road use. The Regulation also requires that vehicles be safe, which in the case of a modification is interpreted to mean at least as safe as the unmodified vehicle. Other states and territories have equivalent in-service requirements, and modifications may require certification under the relevant state scheme (VSCCS in NSW, VASS in Victoria, the Approved Person Scheme in Queensland, or equivalent).

For a 70 Series LandCruiser, which is a light goods vehicle, the Australian Design Rules relevant to a steering wheel are:

• ADR 42/05 General Safety Requirements, covering internal protrusions and electrical wiring
• ADR 90/00 Steering System
• ADR 93/00 Forward Field of View
• ADR 94/00 Audible Warning, covering the horn

The occupant protection rules (ADR 69/00, 72/00 and 73/00) are not applicable to this vehicle category, though the collision tests they specify are useful references when assessing whether a steering wheel modification affects driver safety.

A vehicle with an inactive or faulty airbag system, or a live SRS fault code, is a roadworthiness problem at inspection regardless of what caused it.

Declaring Modifications to Your Insurer

Modifications should be declared to your insurer. This is worth taking seriously for a reason that surprises most people: where a modification has not been disclosed, an insurer's ability to reduce or refuse a claim does not necessarily depend on the modification having anything to do with the loss.

In one 2025 determination by the Australian Financial Complaints Authority, a vehicle was stolen from a hospital car park. The insurer refused the claim because the owner had not disclosed an exhaust change and a tune. A car park theft has no connection to an exhaust, and the refusal was still upheld, on the basis that the insurer had been prejudiced by the non-disclosure.

The lesson is not that modifying your vehicle voids your cover. It is that undisclosed modifications are the risk. Tell your insurer what is fitted to your vehicle, and fit parts you are comfortable declaring.

The PVS Wireless Module Solution

PVS Automotive developed its wireless steering wheel control module specifically to eliminate the clockspring problem entirely.

Instead of replacing the clockspring to route new control signals from an upgraded steering wheel, the PVS wireless module transmits those signals wirelessly from the wheel to a receiver module connected to the headunit's steering wheel control (SWC) input. The result:

• The factory clockspring remains completely untouched.
• The SRS circuit is factory-original.
• The airbag, horn, and all safety-critical wiring remain as manufactured.
• The vehicle's ADR compliance envelope is not affected by the steering wheel upgrade.

This is why the PVS steering wheel kit can be independently assessed for ADR compliance as a complete system. No other approach in the Australian aftermarket for the LandCruiser 70 Series achieves this.

Questions to Ask Before Buying Any Aftermarket Steering Wheel

If you are considering an aftermarket steering wheel for an airbag-equipped vehicle, ask these questions before purchasing:

1. Does the kit include a clockspring replacement? If yes, request the part number and confirm it is vehicle-specific for your exact variant and steering wheel configuration.
2. Has the complete kit (wheel, hub, module, and clockspring if included) been assessed as a system for ADR compliance? Assessment of the wheel alone is not sufficient.
3. Will a qualified automotive engineer in your state certify the installation? Ask this before you buy, not after.
4. Will your insurer cover the vehicle after fitment? Request written confirmation.
5. Does fitting the kit trigger any SRS or warning lights? If yes, that is an active fault in a safety-critical system.