HERNDON, Va. — Volkswagen has reached an agreement to settle claims relating to its 3.0L V-6 TDI engines, committing to buy back a quarter of the vehicles. The automaker will also set aside $225 million for emissions reduction, and pay $25 million to support the use of zero emission vehicles (ZEVs) in California.

The settlement, which awaits final approval, is expected to cost Volkswagen $1 billion, according to the Associated Press. In October, Volkswagen agreed to settle claims around its 2.0L engine for $14.7 billion.

The Dec. 20 settlement covers about 83,000 Volkswagen, Audi, and Porsche vehicles. About 20,000 vehicles would be eligible for buy-backs, and Volkswagen has said it could bring 63,000 vehicles into compliance.

Volkswagen will also pay $225 million to an environmental trust created as part of the earlier settlement. In October, Volkswagen agreed to contribute $2.7 billion to the trust. About $41 million will go to the California Air Resource Board (CARB), according to the board.

Lastly, Volkswagen will provide $25 million to CARB by July 1. The money will be used to expand initiatives such as replace-and-upgrade programs for heavy polluting vehicles in disadvantaged communities and the Clean Vehicle Rebate Project. The latter provides rebates and financial assistance for purchasing ZEVs.

Vehicles covered by the 3.0L settlement include 2009 to 2016 model-year Touareg, 2009- to 2015-MY Audi Q7 and 2013- to 2016-MY Porsche Cayenne Diesel. Other models include 2014-MY, 2015-MY, and 2016-MY Audi models, including the A6, A7, A8, A8L, and Q5.

"This settlement highlights the fact that cheating to get a car certified has consequences for air quality and the public's health — and that cheaters will be caught and held accountable," said Richard Corey, CARB's executive officer. "Because California is able to enforce its vehicle regulations, CARB was instrumental in uncovering the cheating in the 3-liter, and before that, in the 2-liter diesel engines. The mitigation in this settlement will now help California address its serious air quality and climate challenges with a focus on putting the very cleanest vehicles in disadvantaged communities where they are needed most."

U.S. district court Judge Charles R. Breyer must still approve the 3.0L settlement.