General Motors ordered dealers to stop selling the 2013 and 2014 versions of its most popular car, the Chevrolet Cruze sedan, because of a problem with air bags made by the Japanese supplier Takata, whose products are already the subject of a large recall of other vehicles, reported The New York Times.

G.M. said about 33,000 Cruzes may have a faulty driver’s side air bag inflator — the potential result of the wrong part being used.

“We are working diligently with the supplier of the defective part to identify specific vehicles affected and expect to resume deliveries by the end of this week, once those vehicles are identified,” a G.M. spokesman, Greg Martin, said.

Takata devices are already the subject of a recall involving millions of vehicles made by Ford, Chrysler, Honda, Mazda, Nissan, Toyota and BMW. The Takata-produced inflator in those vehicles may contain propellant that can explode in certain situations.

The problem that G.M. announced on Wednesday involves a different aspect of Takata’s inflators — how they are assembled. It was unclear how use of the wrong part would affect the air bag.

“Theirs is a chemistry issue, and ours is a mechanical issue,” another spokesman for G.M., Jim Cain, said.

A spokesman for Takata in Tokyo, Toyohiro Hishikawa, said the company was unaware of General Motors’ decision and could not comment. He said that Takata was a long-term supplier of the automaker.

It is one of the busiest times of the year for auto dealers, as car buyers flock to showrooms ahead of the summer season. The Cruze is G.M.’s best-selling car, with 32,393 sold last month in the United States, up 41 percent from the previous year.

For now, Cruzes will remain on the lots of dealers. Mr. Cain said G.M. was discussing what to do about affected Cruzes that had already been sold. “We’re working through that right now,” he said.

It also became clear on Wednesday that there was a second case in which the company knew it had a safety problem but did not act decisively. That echoed its recent recall of millions of small cars, including the Chevrolet Cobalt, because of a faulty ignition switch that could shut off the engine, disabling the air bags and resulting in a loss of power assist to the steering and brakes.

The automaker portrayed that defect, which has been linked to 13 deaths, as an isolated episode, the fault of a malfunctioning bureaucracy, not an attempt at deceit. However, in May, federal regulators said the automaker broke the law, and it agreed to pay a maximum fine of $35 million.

The newly disclosed case involves the ignition on many of the same vehicles. However, the problem is different. It involves whether the ignition key can be pulled out of the steering column without the automatic transmission being in park or with the engine running. That violates a federal safety standard intended to prevent vehicles from rolling away.

The details were outlined in a report by General Motors, which was sent to the National Highway Traffic Safety Administration late in April. However, it was not posted on the agency’s website until recently. A spokeswoman for the agency did not immediately respond to a request for comment.

The report says that by early in the last decade, the company had hundreds of reports of owners who said they could remove the ignition key without the transmission being in park with the engine running. Many were on the 2003-4 Chevrolet Cobalt and Saturn Ion.

In June 2005, the automaker decided to change the ignition cylinder, into which the key was inserted. That new part would be used on 2006 models, including the Cobalt and Ion. But the automaker did not, at that time, conduct a recall.

It was not until April — as G.M. was under intense pressure from federal regulators and legislators over the Cobalt deaths — that the company decided on a recall. It affected about 2.1 million vehicles, including some models that had the new part. The automaker said it was aware of one injury related to a rollaway vehicle but no deaths.