Warning system and warning method for a motor vehicle having a high-voltage battery

A warning system comprising,

• a battery housing;
• an underride protection device;
• a spatially closed cavity;
• a pressure sensor configured to measure a pressure difference in the spatially closed cavity between the underride protection device and the battery housing, wherein the pressure sensor is arranged within the battery housing laterally to a battery;
• and
• an evaluation device, wherein the spatially closed cavity is arranged in a vertical direction of the warning system above the underride protection device and below the battery housing and is configured to change a volume of the spatially closed cavity upon a deformation of the underride protection device under the action of a predetermined external force on the underride protection device, the pressure sensor is further configured to detect a pressure change value, which describes a pressure change of the pressure in the spatially closed cavity due to the change in the volume of the spatially closed cavity, and to provide the pressure change to the evaluation device, and the evaluation device is configured to provide a warning signal after the detected pressure change value is greater than a predetermined limit change value.