Add Yahoo as a preferred source to see more of our stories on Google. When you leave your car parked for a while, it enters "sleep" mode, but it isn't fully off. Certain systems, like alarms, keyless ...

When you leave your car parked for a while, it enters "sleep" mode, but it isn't fully off. Certain systems, like alarms, keyless entry receivers, and onboard computers remain active. Modern vehicles, ...