(Bloomberg) -- Volkswagen AG was given 45 days to plan arecall of models with 3.0-liter dieselengines found to contain software that Californiaregulators consider a possible “defeat device” that can distortemissions tests.

The California Air Resources Board (CARB) is demanding the fixfor VW, Audi and Porsche models from the 2009 model year on,the agency said Wednesday in a statement. VW’s Audi brandalready said earlier this week it would resubmit a revised versionof the software, which it hadn’t originally disclosed forregulatory review.

Audi told regulators the device played a role in changing howthe vehicles operate during emissions testing, but stopped short ofsaying it cheated in the same way that Volkswagen has admitted tousing software to rig tests for its smaller diesels. However, CARBis treating the 3.0-liter software device as if it cheated on thetest, said Dave Clegern, an agency spokesman.

The 3.0-liter diesel discussion is part of Volkswagen’s effortto address its emissions scandal on three fronts: cheating softwareinstalled in about 11 million vehicles worldwide with 1.2-, 1.5-and 2.0-liter engines; irregular carbon dioxide ratings on about800,000 vehicles; and the questionable software in larger dieselengines in the U.S. The company said this week it’s nearingapproval to repair most of the rigged engines in Europe, by far thebiggest market in which Volkswagen’s dirty diesels weresold.

The shares extended their longest streak of gains sinceSeptember 2010, climbing 4.7% to 125.95 euros at 9:26 a.m. inFrankfurt. Volkswagen has lost more than 10 billion euros ($10.6billion) in market value since its emissions scandal broke on Sept.18.

Managing emissions

The software in the 3.0-liter engines wasn’t designed to cheat,Audi spokesman Udo Ruegheimer said in a phone interview. Many carshave devices that change the way engines perform and manageemissions for different kinds of driving, and that’s legal, hesaid. In this case, the software managed temperatures of theexhaust-cleaning system to account for the fact that engines arecolder shortly after starting, Ruegheimer said.

Audi, which made the engines for its vehicles as well as forPorsche and VW, will be discuss this with CARB over the next 45days, he said.

The fix for 85,000 Audi, VW and Porsche cars with the 3.0- literdiesels is expected to cost roughly 50 million euros. The largerengine is used in the Audi A6, A7 and A8 sedans; Q5 and Q7 sportutility vehicles; and the Porsche Cayenne and VW Touareg SUVs.

Clegern said the device in the 3.0-liter engines has a timerthat shuts it off shortly after the test cycle used to make surethe vehicle’s emissions meet clear-air rules. That’s one reasonCARB thinks the software was designed to cheat, he said.

When regulators first disclosed the issue with the largerengines in early November, Volkswagen said they didn’t have asoftware cheat like the smaller diesel motors did. Then Audi in aNov. 19 meeting admitted to using Auxiliary Emissions ControlDevices in the 3-liter engines that were not disclosed to theCalifornia agency, according to a letter dated Wednesday from CARBto VW, Audi and Porsche. That is a violation of law, according tothe letter.

The U.S. Environmental Protection Agency said in an e- mailedstatement Wednesday that it continues to work closely with theCalifornia board on issues with the 3.0-liter engines.

Copyright 2018 Bloomberg. All rightsreserved. This material may not be published, broadcast, rewritten,or redistributed.