WASHINGTON—Volkswagen AG’s U.S. unit will pay $3.5 million to resolve a lawsuit by the state of Illinois against the German automaker for updates of emissions software arising from the 2015 diesel cheating scandal. Last month, the U.S. Supreme Court rejected Volkswagen’s bid to avoid lawsuits filed by officials in other states seeking damages. Volkswagen had earlier warned of potential astronomical damages in the state and local suits. “Volkswagen intentionally tampered with vehicles it claimed to be environmentally friendly but were actually releasing harmful emissions,” Illinois Attorney General Kwame Raoul said in a statement. The Illinois settlement is worth about $300 for each of about 12,000 vehicles. “This agreement will fully resolve Illinois’s legacy claims and put this matter behind the company as we focus on building a future of sustainable mobility,” Volkswagen said. In September, Volkswagen agreed to pay $1.5 million to settle environmental claims with the states of New …