Stellantis (STLA) unit FCA US reached a settlement with the California Air Resources Board for $4.2 million in violations of air quality regulations, the emissions regulator said Monday.

The settlement involves model years 2014 to 2016 Ram ProMaster 1500, 2500 and 3500 vehicles, CARB said. These vehicles were found to have an unapproved device that circumvented emissions control, resulting in almost 55 tons of excess nitrogen oxides emitted outside of certification testing, the regulator said.

FCA will recall the vehicles to modify the emission control system as part of the settlement, CARB said.

Stellantis did not immediately respond to MT Newswires' request for comment.