Volkswagen, embroiled in an expanding scandal over its intentional cheating of Environmental Protection Agency emission standards with a so-called defeat device, has at least temporarily abandoned plans to include diesel models in its 2016 lineup, a media report said. The decision came to light late after Volkswagen’s US chief executive, Michael Horn, released written copies of testimony he is expected to give before Congress on Thursday (8 October).

The Los Angeles Times said Horn offers “a sincere apology for Volkswagen’s use of a program that served to defeat” emissions tests in the testimony and adds “We have withdrawn the application for certification of our model year 2016 vehicles.” He said the automaker was in discussions with the EPA and the California Air Resources Board – which oversees the nation’s toughest clean air rules — to find an acceptable “emissions control strategy”.

But Horn’s statements did not make clear what sort of rememdy the company was proposing for the VW vehicles already on the road that currently cannot pass emissions tests, the LA Times noted.

Horn said: “We described to the EPA and CARB that our emissions control strategy also included a software feature that should be disclosed to and approved by them as an auxiliary emissions control device (AECD) in connection with the certification process.”

Kelley Blue Book analyst Karl Brauer told the paper that wouldn’t reassure current owners waiting to know what can be done to make their vehicles compliant – a simple software update or the retrofitting of more complicated hardware.

“They’ve abandoned the entire 2016 model year diesels, and that’s not good news for owners,” Brauer said. “It suggests that the fix is probably not going to be easy. It suggests that the fix involves so much challenge that they’re not even going try to make the 2016s work.”

According to the paper, the EPA issued a statement saying Volkswagen had withdrawn certification application for 2016 vehicle models that use the two-litre diesel engine including the Audi A3 and VW Beetle, Beetle Convertible, Golf, Golf Sportwagen, Jetta and Passat models.

A Volkswagen representative told the LA Times the Touareg diesel, which uses a three-litre engine, was not affected by the EPA discussions and would be part of the 2016 line-up.

Horn said in his testimony he was taking “complete responsibility” for the scandal, adding: “these events are deeply troubling. I did not think that something like this was possible at the Volkswagen Group. We have broken the trust of our customers, dealerships and employees, as well as the public and regulators.”

Volkswagen has admitted installing cheating software in 11m diesel vehicles worldwide and an estimated 482,000 of those were sold and registered in the US, about 15% in California, the paper said.