It doesn’t really come as a surprise that U.S. Senate investigators are widening the scope of the inquiry into General Motors’ decade-long failure to recall cars with a defective ignition switch to now also focus on the supplier which made the flawed part.


The supplier, Delphi Automotive, didn’t permit its employees to be interviewed by Anton Valukas, the former federal prosecutor who conducted an internal inquiry into GM’s handling of the switch problem and who wrote a scathing report on the automaker’s corporate culture. Unlike Valukas’s company-financed investigation, however, the Senate Commerce Science and Transportation Committee has the power to subpoena witnesses. That committee will begin a hearing July 17.


This follows an initial hearing held last April in which senators had asked for information about whether the parts supplier pushed back against GM after the automaker apparently didn’t accept a proposed fix to the switches. At the time, a group of senators had written to Delphi Chief Executive Officer Rodney O'Neal, that they understand “… a fix was proposed by Delphi regarding the ignition switch in 2005 but GM did not adopt the change,” the letter said.


“As we continue evaluating the GM recall it is critically important that we understand the decisions made by Delphi and the company's interaction with GM,” the letter continued.


Numerous documents now made public by the investigation contain a number of exchanges between GM engineers and Delphi employees over an ignition switch that both parties recognized as below standard. It’s this “who knew what, and when” dialog that now comes under investigation.


Interestingly, Mary T. Barra, GM’s chief executive, has said that more recalls may be on the horizon as the company continued to thoroughly investigate safety issues.


“We’re going to continue to look at the data that we get, and we’re going to take the action that we need,” Barra told NBC’s Today show. “If we find an issue, we’re going to deal with it.”


That may already be happening. GM has also recalled about 29,000 2013-14 Chevrolet Cruze models for an air bag malfunction. The air bags, made by the Takata Corp., were assembled with an incorrect part which could cause the metal casing of the inflator to rupture. Such a rupture could send metal shards into the passenger compartment, GM said.


A number of other automakers have recalled about three million vehicles because of air bags made by Takata with inflators that could also explode. However, the problem with those systems involved the propellant inside the inflator being improperly manufactured, Takata has said.


Perhaps with GM’s troubles in mind, Chrysler leadership recently recalled almost 700,000 vehicles in North America because its ignition switches—like those in some GM vehicles—can slip from the “run” to the “accessory” position while driving. The Chrysler action expands an earlier recall of 2010 Chrysler Town and Country and Dodge Grand Caravan minivans and Dodge Journey crossovers. The new recall adds models produced from 2007 to 2009.


Chrysler said in a statement that the expanded recall is being done “out of an abundance of caution.”


There are two elements that stand out in all this. The first is, in general, the need to work closely with key suppliers to recognize the need for critical design changes and then ensure those changes are being made and enforced with the correct new parts. The second point is to wonder about the ramifications for the auto industry. Will companies be quicker to announce recalls? Will the government scrutinize auto recalls more closely?


What are your thoughts—on relationships with key suppliers, recalls or the auto industry?