Volvo Group said it could not yet determine the impact of a faulty component on its North American trucks as it was still evaluating the scope of the problem.

Volvo, the world’s second-largest truckmaker, has uncovered a faulty component in the emissions-control setup of vehicles widely sold in Europe and the U.S., the manufacturer’s biggest markets.

Volvo AB, the world’s second-biggest maker of trucks, is about to increase its market value by about a fifth, if analyst estimates are to be believed.

AB Volvo reported first-quarter net income and revenue increased despite supply chain constraints in North America’s surging truck market.

BEIJING — The Chinese owner of Sweden’s Volvo Cars is buying a stake in truck manufacturer AB Volvo, expanding a portfolio of vehicle brands that includes shares in Malaysia’s Proton and Britain’s Lotus.