This helps the vehicle's battery from draining the battery in case the interior courtesy lamps, reading lamps, visor vanity lamps, trunk lamp, underhood lamp or glove box lamps are left on. If any of these lamps are left on while the ignition is off, they will automatically turn off after 20 minutes. The lamps will not come back on again until you do one of the following:

If the vehicle has less than 15 miles (25 km) on the odometer, the battery saver will turn off the lamps after only three minutes.