Signal Jammers – Why Your Car Might Not Lock

Criminals also use signal jammers, which don’t steal the car itself but can stop it from locking. On cars that rely on a button-press on the key fob or walk-away automatic locking using a traditional (non-UWB) key fob, a jammer nearby can interfere with the car receiving the lock signal. The driver walks away believing the car is secure, when in fact it remains unlocked. This technique is commonly used to steal items from inside vehicles.

In real-world car theft, these jammers are designed to interfere with the radio signals used by traditional (non-UWB) key fobs.

UWB key fobs, Phone-as-Key (BLE), and Digital Key 3.0 work differently. Instead of waiting for a lock command, the car locks automatically when it detects that the key fob or phone is no longer nearby. Because there is no separate “lock” signal to block, the simple jammers commonly used by thieves are ineffective against these systems.

Digital Key (NFC) requires a physical tap of a phone or card against the car. Because this involves direct contact, they cannot be jammed at all.

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