Chrysler Group has won a key ruling in its bid to keep documents sealed in a closely watched case over an alleged defect in millions of its vehicles.

The U.S. Court of Appeals for the Ninth Circuit affirmed a federal judge’s ruling that sealed documents in a case alleging Chrysler vehicles had a defective power module. The Aug. 23 decision comes after Chrysler failed to convince the U.S. Supreme Court to take up its petition to reverse an earlier ruling in which the Ninth Circuit found the trial judge used an incorrect standard to seal the records.