A federal judge could decide soon if G.M. will be required to inform owners who have cars with bad ignition switches to stop driving them. The do not drive request would be in place until they are fixed. The judge hearing the case said more information is being reviewed.

Here's the problem: the switches can stop working without notice. This can happen when the car goes over a bump or if the ignition key is somehow jarred by mistake. When that happens the engine and the entire electrical system would shut down as well.

Reports indicate the vehicles effected have been involved in at least 30 crashes. At least 12 have been killed.

G.M. Vehicles Recalled - Photo by Getty Images