What does a flashing check engine light mean on a 2003 VW jetta?

A flashing check engine light on a 2003 VW Jetta indicates a serious issue, often related to the engine or emissions system, such as misfiring or a failing catalytic converter. This warning suggests that the vehicle may be damaging the engine or emissions components if driven further. It's advisable to stop driving the car and have it diagnosed by a mechanic as soon as possible to prevent potential damage.