Volkswagen can’t sell 2016 diesels in the U.S.

Volkswagen of American won’t be able to sell 2016 diesel 2.0-liter engine models in the United States, and the carmaker has withdrawn its application for EPA certification.

If the manufacturer complies with U.S. emissions standards, it can again begin selling its vehicles currently in violation of emissions policies.

Volkswagen had been awaiting EPA approval for the 2016 diesels, but withdrew its request as part of ongoing discussions with U.S. regulators following emissions violations.

Volkswagen of America CEO Michael Horn disclosed the decision in written testimony he delivered at a hearing before the House Energy and Commerce committee.

In his testimony, Horn said part of VW’s emissions control strategy included a “software feature” that should be “disclosed to and approved by” regulators as an “auxiliary emissions control device,” which are legal under U.S. emissions rules.

It’s unclear what that software feature does, exactly, but a Volkswagen of America spokeswoman said it is different from the software classified as a “defeat device” by regulators that activated full emissions controls only in lab tests while deactivating the controls on the road.

In his written statement, Horn apologized for the violations of U.S. emissions rules but stopped short of saying when a fix for affected diesel-powered vehicles would be available.

Horn outlined the sequence of events leading up to the EPA’s disclosure of VW’s emissions violations last month, and what the company has done since. But he did not give a timeline for repairs to bring the roughly 482,000 VW models with 2.0-liter diesel engines sold since 2008 with the illegal software into compliance with U.S. regulations.

Horn said he was informed in the spring of 2014 that VW may have an emissions compliance problem when West Virginia University published research showing the real-world emissions of two diesel-powered VW models were much greater than lab tests indicated.

Horn says he was informed that the “possible emissions non-compliance” issue could be remedied, and that VW engineers would work with regulators to resolve the issue.

Volkswagen issued a recall is December 2014 to reprogram the emissions calibrations on some of its diesel vehicles. Tests conducted by the California Air Resources Board following the recall found the higher real-world emissions persisted.

Horn called violations that have upended the company’s management ranks and sent its stock price tumbling “deeply troubling” and offered a “sincere apology” for the company’s use of emissions control software that masked real-world emissions.

Horn’s statement detailed that each of the three generations of VW’s 2.0-liter diesel engines involved will require a different repair.