The Volkswagen Group has reached a preliminary agreement with U.S. regulators to address 83,000 3.0-liter V-6 diesel vehicles with illegal "defeat device" software.
The agreement—which covers a variety of SUVs and sedans sold by Audi, Porsche, and Volkswagen—must still be finalized and approved by a federal judge.
Affected cars will either be modified to meet emissions standards or bought back from their owners, prices still to be determined.
DON'T MISS: VW 3-liter diesel updates OKed, but buyback negotiations continue
In addition to the modifications and buybacks, VW agreed to contribute additional funds for environmental remediation and zero-emission vehicle infrastructure, on top of what the previously-approved settlement for 2.0-liter diesel models calls for.
All told, Volkswagen could end up spending $1 billion on the 3.0-liter diesel settlement, according to Reuters.
That figure was quoted by Cynthia Giles—U.S. Environmental Protection Agency (EPA) assistant administrator—in response to the announcement of the preliminary 3.0-liter diesel agreement earlier this week.
2015 Audi Q7 TDI
The affected vehicles include TDI diesel versions of the Audi A6 and A8L sedans, A7 hatchback, and Q5 and Q7 SUVs, as well as the Porsche Cayenne Diesel and Volkswagen Touareg TDI SUVs.
Under the preliminary agreement, VW will modify 75 percent of the 83,000 affected vehicles to meet emissions standards, and offer buybacks for the remainder.
Any modifications must be approved by both the EPA and California Air Resources Board (CARB).
ALSO SEE: VW diesel probe focuses on missing phones: 'bright red flag,' says FTC
A Volkswagen statement describing the agreement indicated the company may try to buy back more vehicles if modifications aren't approved.
Details of the buyback are still being negotiated with the plaintiffs' steering committee, with the deadline for submitting a completed agreement now set for January 31.
In addition to costs related to the modification and buyback programs, VW has also agreed to pay an additional $200 million into a federal emissions-remediation fund.
2015 Porsche Cayenne Diesel
That's on top of the $2.7 billion previously committed to the fund as part of the 2.0-liter diesel settlement.
As part of a separate settlement with the state of California, Volkswagen also agreed to pay $25 million to support the deployment of zero-emission vehicles in that state, part of an overall 10-year, $2 billion fund to go toward zero-emission vehicle infrastructure.
MORE: Volkswagen fights demands for Dieselgate documents, Bosch joins too
Supplier Bosch is also expected to pay $300 million to settle a suit related to the VW diesel scandal, according to Reuters.
Last year, U.S. diesel owners filed a suit against Bosch, claiming it helped design the "defeat device" software used by Volkswagen to cheat on emissions tests.
diesel and AdBlue fillers in Audi Q7 TDI
Bosch previously denied the claims made in the lawsuit.
In Canada, Volkswagen plans to spend C$2.1 billion ($1.6 billion U.S.) to address excess diesel emissions, reports Reuters.
The money will be used to compensate owners of 105,000 diesels in Canada, and to modify or buy back those cars.
VW will also pay the Canadian government a C$15 million ($11.2 million U.S.) in fines and fees.