My mother in law bough a crossfire and loves the car. The other day she drove to a store went in and came out and the car would just start and die. Twice this happened till no crank. Unhook battery and it will do the same sequence. Keyless entry works.... The dealler is trying to tell me that the pcm is corrupt and needs to be replaced along with the skreem and skim moduel and keeys to the tune of 5k. I'm having a hard time believing this is the necessary repair. Also limited mechanics with any knowledge of these cars up here in montana. Any help would be great