Zündschloss

Zündschloss, or ignition lock, is a component in motor vehicles that allows the engine to start and provides power to the vehicle’s electrical systems. Traditionally it consists of an ignition cylinder connected to an ignition switch and, in many cars, a steering-column lock. Modern systems often integrate the lock with an electronic immobilizer and a transponder in the key or key fob.

Operation typically involves inserting a key and turning it through several positions. From Off to Accessory, On, and Start. Off cuts power to most circuits and may engage the steering lock. Accessory powers auxiliary electrical equipment. On enables the ignition system and essential circuits, while Start engages the starter motor for a short moment. Releasing returns the key to On. In electronic or smart-key systems, a push-to-start button or proximity key may replace the physical turning action, using electronic authentication to enable starting.

Security and variants include traditional mechanical locks and more advanced electronic designs. The ignition system often forms part of an anti-theft setup, with immobilizers that verify a code or cryptographic credential from the key or fob. If the immobilizer does not recognize the key, the engine will not start. Rolling-code transponders and encrypted communication have become common to deter theft. Some vehicles also integrate the ignition with starter switches or multiple systems, while others use conventional mechanical components complemented by electronic controls.

Maintenance and issues can arise from wear in the key or cylinder, causing stiffness or key extraction problems. Replacing or rekeying the cylinder, repairing contacts, or diagnosing immobilizer faults may be required if starting problems occur.