If a new key or transponder is not correctly programmed to match the vehicle’s immobiliser system, it will not work. This can happen during replacement keys or when attempting to program a new key without the proper equipment.

Most transponder keys have a small battery inside. If this battery dies, the key may no longer communicate with the vehicle’s immobiliser system.

Keys and transponders can become physically damaged through accidents, exposure to moisture, or other means. Physical damage can prevent the key from functioning properly.

Sometimes, the ignition cylinder, which reads the transponder signal, can become faulty. This can result in the immobiliser not recognizing a correctly programmed key.

Wiring problems within the immobiliser system, such as a loose or damaged connection, can prevent the transponder from communicating with the vehicle’s computer.

The immobiliser’s electronic control unit (ECU) can fail, rendering the immobiliser system inoperable. This often requires replacing the ECU and reprogramming keys.

Radio frequency interference or electronic devices emitting strong signals in close proximity to the vehicle can disrupt the communication between the transponder and the immobiliser system.

A weak vehicle battery or low voltage can sometimes cause intermittent issues with the immobiliser system. It may not have enough power to correctly identify and authorize the transponder.

The antenna or reader coil that receives signals from the transponder can become damaged or faulty, leading to communication problems.

Errors in the immobiliser’s software or programming can cause issues. This may require reprogramming or updating the immobiliser system.

In some cases, tampering or attempted theft can damage the immobiliser system, rendering it inoperable.