Mercedes-Benz USA and parent company Daimler AG have agreed to pay $149.6 million to settle allegations that the automaker secretly installed devices in hundreds of thousands of vehicles to pass emission tests, a coalition of attorneys general announced Monday.

According to the coalition, between 2008 and 2016, the German automaker equipped more than 211,000 diesel passenger cars and vans with software devices that optimised emission controls during tests but reduced the controls during normal operations. The devices enabled vehicles to far exceed legal limits for nitrogen oxides, a pollutant that can cause respiratory illnesses and contributes to smog.

The States alleged that Mercedes installed the devices because it couldn't reach design and performance goals, such as fuel efficiency, while complying with emissions standards. The automaker allegedly concealed the devices from state and federal regulators and the public while marketing the vehicles as “environmentally friendly” and compliant with emissions standards.

A spokesperson for the automaker had no immediate comment.

Daimler AG and Mercedes-Benz USA already agreed in 2020 to pay $1.5 billion to the U.S. government and California State regulators to resolve the emissions cheating allegations.