Crashing
If an uncontrolled vehicle runs into an obstacle or another vehicle, it crashes. This deals double the vehicle’s collision damage to the uncontrolled vehicle and to the obstacle it ran into, and stops the uncontrolled vehicle’s progress. If the uncontrolled vehicle crashes into a controlled vehicle, the other pilot can attempt a Piloting check to avoid being hit as if it were being rammed (see Ram on page 279). If that pilot avoids being hit, the uncontrolled vehicle continues to move as detailed in Uncontrolled Vehicles above.
Source
Core Rulebook pg. 280