SAN FRANCISCO — Google Inc.’s driverless car spinoff Waymo LLC didn’t get much of what it wanted out of preliminary injunction ruling against rival Uber Technologies Inc. on Monday. But it still has succeeded in putting extraordinary pressure on Uber to account for a trove of stolen files.

In a ruling early Monday morning, U.S. District Judge William Alsup of the Northern District of California all but ordered Uber to fire the star engineer behind its autonomous vehicle program, Anthony Levandowski, if he won’t turn over the 14,000 files he took from Waymo—where he worked prior to founding a self-driving car company acquired by Uber.