An Attempt to Be Discreet

Service bulletins can be an inexpensive substitute for a recall. In January 2013, for example, G.M. engineers estimated that it would cost $41.3 million to change the ignition switches in more than 778,000 vehicles, including Cobalts and Pontiac G5s. While there is no data available on the cost of repairs that resulted from the letter to dealers and owners, experts say the financial costs and the hit to the company’s reputation were likely to be softer with the relatively discreet bulletins.

The Times analysis of service bulletins was limited to General Motors. The safety agency declined to comment on how G.M. compared with other automakers, but its top defects investigator, Frank Borris, last year scolded G.M. over its lack of responsiveness on safety issues, in contrast to its peers.

“The general perception is that G.M. is slow to communicate, slow to act, and, at times, requires additional effort,” Mr. Borris wrote to Carmen Benavides, director of product investigations at G.M., in a July 2013 email. The company, he added, required effort from the agency “that we do not feel is necessary with some of your peers.”

In one case, he reprimanded G.M. for issuing a service bulletin in July 2012 for a “fairly obvious” safety concern over a defective air bag in the Buick Verano and Chevrolet Cruze and Sonic. G.M. recalled some of the cars in October 2012, expanded the recall in January 2013 and eventually recalled even more in November.

Mr. Borris also cited four other instances in which the agency questioned G.M.’s use of technical bulletins to deal with safety issues and pressed for recalls, including the case of the 2013 Chevrolet Malibu, which was recalled in May 2012 for an air bag defect.

The automaker’s top product executive, Mark Reuss, declined to say whether G.M. had a pattern of issuing service bulletins for safety problems before eventually ordering recalls.

“I don’t have any data on that,” he said last week when asked by The Times at an industry event in New York. “We are definitely working on being responsive.”