GM’S Big Recall

In the auto industry, recalls, once rare, are now so frequent that they barely warrant mention in the daily news. Of the recent batch, the mother of them all is of course the General Motors ignition switch problem which at press time has resulted in a known 13 fatalities. The problem is simple: the key rotates back to the “off” position, shutting down the engine and power steering as well as the air bags. That’s not good, but it should be noted that the effect is the same as stalling the engine while in motion…steering control is not lost, but the lack of power assist makes it more difficult. Braking is similarly not an issue, as almost all modern systems are boosted by engine vacuum and incorporate a check valve to maintain this boost long enough to bring the car to a safe stop. Tragic as the fatalities are, the defect is not as serious as the mass media would have us believe.

If you’re a Tier One or Two, you either build the part to the customer’s drawing or you design the part to your customer’s specification, but either way running changes to improve reliability and reduce cost (or both) are common. In the case of the GM ignition switch, reports of the keys turning back resulted in a running change to the design, one which was not accompanied by a change in the part number. This means that it’s difficult-to-impossible to determine which switches are bad and hence, a massive recall.

The mass media are reporting this as if it’s a criminal conspiracy. The fact is, running changes are commonly tracked by the print revision numbering system, not by part number. Changing part numbers with each print revision would cause supply chain chaos, adding to confusion that already exists when new parts carry numbers that supersede older designs. The move to standardize common parts across multiple models is not only a unit cost control measure; it is also intended to control part number proliferation. That’s a good thing, but if OEM customer feedback results in a demand for changes that significantly alter the part’s form, fit or function, the customer will ask for and get a new part number.

Changing to an internal spring with a slightly higher tension wouldn’t justify a new part number since the problem was a convenience issue, not a safety problem when it was first noticed. Has the recall hurt GM? Less than many believed, as sales remain strong. Other manufacturers are cleaning house with recalls of their own, but with the desire to increase parts commonality across multiple models, larger recalls can be expected. Toyota bounced back nicely from their accelerator pedal issue, and GM will do the same.