فنر ساعتی ستون فرمان معیوب

The coiled flat ribbon cable inside a cassette behind the steering wheel, which carries every electrical circuit into a part that rotates.

It is a consumable rather than a component, and that framing is the useful one. The ribbon winds and unwinds through the full range of steering travel every time the wheel is turned, over hundreds of thousands of cycles, and it eventually cracks. Nothing is abnormal about that happening; it is a wear item that simply has no service interval.

What makes it worth recognising is that it takes several unrelated things with it at once. Everything reaching the steering wheel goes through it: the airbag circuit, the horn, the wheel controls, the heated wheel element, and on many vehicles the steering angle signal. So the characteristic picture is a group of failures that look coincidental and are not — a horn that has stopped working alongside dead wheel buttons and an illuminated airbag light is one part, not three faults.

The airbag light is the one that matters and it should set the priority. A cold steering wheel or a silent horn is an inconvenience; an airbag circuit the system cannot verify is not, and the two very often share this single cause.

The diagnostic signature is free and unmistakable: the fault changes with steering wheel position. Something that works with the wheel straight and fails on lock, or comes and goes as the wheel is turned, is this.

One caution on replacement: a clockspring must be centred before fitting, and it is easy to get wrong. Fitted off-centre it has insufficient travel one way and tears itself apart at full lock — often within weeks, which then reads as a faulty new part.