There's dozens of things the computer tests and monitors. When a problem is detected, the computer sets a diagnostic fault code, turns the system off, and turns the warning light on to tell you. The place to start is by having the fault code read and recorded, but be aware, fault codes never say to replace a part or that one is bad. They only indicate the circuit or system that needs further diagnosis. When a part is referenced in a fault code, it is actually the cause of that code about half of the time. First we have to rule out wiring and connector terminal problems, and things like that.
One of the most common problems is a broken clock spring. That's a wound-up ribbon cable in a plastic housing under the steering wheel. As it continues to break, switches on the steering wheel will stop working. Those are usually for the horn and cruise control.
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Wednesday, April 17th, 2019 AT 2:12 PM