A federal judge gave Volkswagen AG another month to come up with a fix for its diesel-powered cars that violate U.S. emissions standards after the German auto maker failed to meet the judge’s initial deadline.

An attorney for Volkswagen said at a hearing Thursday in San Francisco that engineers are working “around the clock” on a fix for some 600,000 vehicles sold in the U.S. that Volkswagen has admitted it equipped with software that tricks emissions tests.

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