Volkswagen said on Wednesday it would take time to get to the bottom of its rigging of diesel emissions tests, hours before the carmaker is due to give updates on its findings to German regulators and U.S. lawmakers.
More than two weeks after it admitted to cheating U.S. emissions tests, Europe's largest carmaker is under pressure to identify those responsible, to say how vehicles with illegal software will be fixed and whether it also cheated in Europe.
"Nobody is served by speculation or vague, preliminary progress reports," Hans Dieter Poetsch told a news conference after being confirmed as the German company's new chairman.
"Therefore it will take some time until we have factual and reliable results and can provide you with comprehensive information," he added, declining to take any questions.
Later on Wednesday, Volkswagen submitted plans to Germany's KBA watchdog to spell out how it would make its diesel vehicles comply with emissions laws. The transport ministry said it had been assured by the company that the deadline would be met.
Transport minister Alexander Dobrindt said authorities were examining whether to make additional demands of Volkswagen.
"My expectation is that the KBA will analyse this report rapidly and comprehensively, and submit possible questions to Volkswagen," he told reporters in Berlin.
In written testimony to a U.S. congressional oversight panel, Volkswagen's top U.S. executive said the carmaker has withdrawn its certification application for some 2016 model year vehicles due to a software feature that should have been disclosed to U.S. and California regulators as an auxiliary emissions control device, or AECD.
Volkswagen separately identified the vehicles as 2.0-litre, 4-cylinder turbodiesel Beetles, Jettas, Golfs and Passats.
A spokeswoman for the U.S. Environmental Protection Agency said the withdrawal also includes 2016 Audi A3 turbodiesels and added that regulators are investigating the nature and purpose of a recently identified AECD that Volkswagen said it included in one or more model years.
AECD is a regulatory term that includes defeat devices, like the software logarithm Volkswagen has admitted using in model years 2009-2015. Michael Horn, who testifies before lawmakers on Thursday, provided no further details but said Volkswagen is working with regulators to continue the certification process.
Both events come as investigations and lawsuits against the company continue to pile up.
According to a letter released on Wednesday, top senators on the U.S. Senate Finance Committee are investigating Volkswagen's actions related to federal tax credits designed to reward consumers for buying environmentally-friendly vehicles.