What does the security light mean on my car dashboard UK?

The security light on your car's dashboard (typically showing an airbag, person silhouette, or seatbelt symbol) indicates your vehicle's anti-theft system is activated. In UK models like the Vauxhall Corsa or Ford Fiesta, this light means the immobiliser is engaged, preventing unauthorised engine starts. Modern UK-spec vehicles from brands like BMW and MINI combine this with alarm systems that monitor doors, bonnet, and boot access. When lit, the system may disable the ignition circuit, fuel pump, or gearbox as theft deterrents. The light normally flashes when armed and stays solid if there's a fault - consult your owner's manual for brand-specific patterns (e.g., Nissan Qashqai uses 3 flashes then pause). If the light stays on while driving, have a qualified mechanic check for faults in the immobiliser circuit, as this could affect MOT compliance.