Volkswagen Has a Fix For Most of Its Emissions-Cheating Cars by Kirsten Korosec @FortuneMagazine November 25, 2015, 2:00 PM EST E-mail Tweet Facebook Linkedin Share icons Volkswagen says a software update and small piece of hardware will fix the majority of the diesel vehicles in Europe ensnared by an ongoing emissions cheating scandal. The controversy affects an estimated 11 million cars globally, including about 500,000 vehicles in the U.S. While the recall will fix millions of cars in Europe, U.S. Volkswagen VLKAY diesel owners will have to wait longer for a remedy. The technical fixes for its EA 189 diesel engines have been approved by Germany’s Federal Motor Transport Authority and the first recalls will begin in January, the Volkswagen Group said in a statement issued Wednesday. In September 2015, Volkswagen became the target of investigations after the U.S. Environmental Protection Agency accused the company of installing illegal software in its turbocharged direct injection (TDI) diesel engines. These so-called defeat devices allowed the vehicle’s nitrogen oxide output to meet U.S. standards during regulatory testing and then produced up to 40 times higher NOx in real driving conditions. Volkswagen says the 1.6-liter EA 189 engine will require a software upgrade and a piece of mesh to be fitted in front of the car’s air mass sensor. The repair is expected to take about an hour per vehicle. Meanwhile, Volkwagen’s 2.0-liter engine will only need a software upgrade to be compliant, the company says. It is also still developing a fix for its 1.2-liter, 3-cylinder engines. Meanwhile in the United States, Volkswagen still faces headwinds, as emissions regulations are more stringent and new accusations have popped up. The EPA and the California Air Resource Board have issued two notices to Volkswagen Group in the past two months, accusing the automaker of developing and installing software that masks emissions. The initial notice alleged that Volkswagen used illegal software on certain 2.0 liter engines for model year 2009-2015 vehicles, including the Jetta, Jetta Sportwagen, Beetle, Audi A3, Golf, Golf Sportwagen, and Passat. A second notice in early November said the company also violated the Clean Air Act when it used illegal software in certain vehicles equipped with 3.0-liter V6 diesel engines for model years 2014 through 2016 to circumvent U.S. emissions laws—an allegation that pulled in Porsche into the widening scandal, as well as more Audi and VW models. Audi designed the 3.0-liter engine. Volkswagen initially pushed back on the most recent allegations, though the automaker eventually admitted that the software did indeed include one or more Auxiliary Emission Control Devices that it had failed to disclose in their applications for certificate of conformity for each model. Audi said in a statement Monday that its A6, A7, A8, Q5 and Q7 diesel models dating back to 2009 were all impacted, as well as the VW Touareg and Porsche Cayenne, which have been using the diesel engines since 2013 in the U.S. Audi said it can correct the issue with a software update, which is expected to cost in the “mid-double-digit millions of euros.” Here’s a video from Volkswagen that explains the technical fixes approved by Germany’s regulatory agency. Sign up for Data Sheet, Fortune’s daily newsletter about the business of technology.