Executives at Porsche say they had no idea the Cayenne Diesel used a defeat device, and have announced that they are discontinuing all sales immediately.

“Late this morning, Porsche Cars North America, Inc. received a notice of violation from the United States Environmental Protection Agency (EPA) regarding the 2015 Porsche Cayenne Diesel,” the company said in a release yesterday.

“We are surprised to learn this information. Until this notice, all of our information was that the Porsche Cayenne Diesel is fully compliant.”

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Today, Porsche followed up with a statement that the company will “voluntarily discontinue sales of model year 2014 through 2016 Porsche Cayenne Diesel vehicles until further notice.”

Officials with the EPA are continuing to investigate diesels built by Volkswagen AG, which includes the Audi and Porsche brands. A 3.0-liter diesel engine, the second Volkswagen-built engine to be found guilty of using a defeat device to cheat emissions tests, powers the Porsche Cayenne Diesel. The EPA estimates that about 10,000 vehicles – including the 2015 Cayenne Diesel, 2016 Audi A6 Quattro and the 2014 VW Touareg – use this flawed engine.

Porsche said it was working “intensively” to find a fix for its vehicles, and assured all current Cayenne Diesel owners that it’s safe to continue driving these crossovers in the meantime.