Ultra Wide Band Operation

With the introduction of ultra wide band technology, recognizing the position of the smart key requires 2 pieces of distance information. The 2 passive entry transceivers are located in the headliner, 1 at the front and 1 at the rear, enabling full coverage inside and outside of the vehicle.

The following process takes place to validate the smart key:

• The Remote Function Actuator (RFA) receives a door lock/unlock request.
• On receipt of the door lock/unlock request, challenge data is sent out from the RFA, via Low Frequency (LF) antenna at 125 kHz to the smart key.
• The smart key responds to the LF signal, processing the received message and replying to the vehicle using a separate Radio Frequency (RF) channel.
• This response is received by the Remote Function Receiver.

In addition the RFA sends a separate challenge through the passive entry transceivers to the smart key. The RFA sends this separate challenge in order to authenticate and obtain the smart key position with accuracy, using the following process:

• The challenge data is sent from the RFA via Local Interconnect Network (LIN) to the passive entry transceivers.
• The passive entry transceivers process and transmit the data, via a separate RF signal, at 3.99 GHz (4.5 GHz in China) to the smart key.
• On receipt of the signal the smart key responds with an authentication message back to the passive entry transceivers. The response is sent through a RF signal.

When the smart key is validated the system operates in the normal way.