The apparent cause of the problem is the accumulation of brass powder, that wears off the electrical contacts inside the turn signal switch.this powder collects in small trails of grease that track from one contact to another.when the concentration of brass in the grease gets high enough, it can cause a high resistance short.this short, in turn can ignite the grease and cause smoke to be emitted from the steering column.the grease used inside the switch, as well as the various plastic components in the column, are fire retardant and will not burn without a sustained heat source.there has been only a single verified incident that resulted in a vehicle fire and this reported fire was small, involving some charring of the steering wheel.all other verified incidents were limited to smoke from the column and minor internal damage to the steering column.
