Here is how the Card starting system operates..

[Ray]

Whether you have handfree or Non hands free the system operates the same way..

When you get in the vehicle and press the start button the system attemps to authenticate at least one Keycard in the following way.

1: The UCH by means of the three starting antennas, generates an RF signal at a frequency of 125KHz. The signal is intended to be received by the Renault Card and contains the identification number of the UCH and an encrypted message.

2: If the Keycard recognises the UCH, it decrypts this message and responds to it on a frequency of 433MHz:

3: If the UCH recognises the Keycard and the response is correct, the UCH moves on to the immobiliser stage. The Starting Antennas stop transmitting as soon as the Keycard has been authenticated.

NOTE: If no keycard responds in handsfree mode, the UCH then interogates the Kaycatd holder.

4: The steering column lock is unlocked by the UCH after authentication of the Keycard by sending a code via the multiplexed network. The steering column send a code to the UCH confirming that it is unlocked, and the A+ ignition line is switched on.

5:After the A+ ignition line is switched on the injection computer sends an encrypted multiplex frame to the UCH. If the UCH recognises the injection computer it responds to it.

6: If the response of the UCH is correct the injection computer is unlocked and the vehicle starts..

Authenticating the Keycard when the engine stops..
To stop the engine the following conditions are required.
1: Vehicle Speed = omph
2: starter button depressed
3: The keycard in the starting area.

The presence of the keycard is very important. In fact, following the press on the stop button, the UCH authenticates the keycard in the same way as when starting.

If handsfree is fitted then there are up to 5 other antennas fitted.. There is 1 in each of the door handles and 1 in the tailgate.. and the infrared presence sensors behind the handles..

The handfree operates in a similar fashion to the starting routine..

The UCH controls the antennas on each side (driver, Passenger, Rear) in the following order:
1: First, the side containing the handle which has been accessed.
2: Next, of no keyvard is detected, it interogates the antennas on the opposite side,
3: Finally if no keycard is detected, it interogates the rear antenna.

The UCH interogates ans authenticates the keycard via the door handle antennas,, tailgate antenna on a frequency of 125KHz.
The keycard if it is recognises its UCH, responds directly to it 433MHz.

The signals transmitted when locking or unlocking the door handsfree are encrypted. These signals are as follows:
1: Seizing of the handle or pressure on one of the closure switches.
2: The UCH by means of the access antennas, generates an RF signal at 125KHz. This signal is intended to be received by the keycard and contains the identification number of the UCH and an encrypted message.
3: If the keycard recognises its UCH, it decrypts the message and responds to it on 433MHz.
4: If the UCH recognises the keycard and the response is correct, the UCH locks or unlocks the doors.