The lock motors on all the doors are activated simultaneously upon a command:

• from the ignition;
• from the front door switches (knobs);
• from the remote control.

Locking operation: when the key is used on one of the two front doors or the remote control is operated when the doors are firmly shut and the front locks locked, all four side doors are locked simultaneously.

The locking of the doors when a speed of 20 km/h is exceeded can be enabled/disabled using the car parameters set-up.

Unlocking operation: when the key is used on one of the two front doors, with front locks locked, or the remote control is operated, all four doors are unlocked.

The remote control works by radio frequencies and must be pointed towards the receiver on the interior light. When the remote control is activated the interior lights switch on for a set time.

This system is controlled by body computer in the driver's glove compartment.

The control unit also carries out a series of safety checks.

• The control unit monitors lock status. A lock command is issued only when all doors are properly closed : if the operated door is not properly closed, the control is blocked. if the door opposite the operated door is not properly closed, an immediate repulsion takes place (i.e. the opposite manoeuvre is carried out to realign the locks).
• if there is a rapid succession of alternating lock/unlock commands, the control unit only carries out the first three commands without activating the inhibition. Similarly if 10/11 opening and closing actions are carried out in 25 seconds (the last is always an unlock), the circuit is then inhibited for about 30 s.
• the circuit can be further inhibited if the battery voltage falls below 9 V within 20 ms. from the start of activation of the lock/unlock actions. During the inhibition time (30 s), the commands are ignored. The commands are ignored if the voltage is less than 8V
• in absence of one of the engine lock connectors, the computer quickly carries out a repulsion. The next command activates only the functioning lock.

The body computer checks the motor actuations, i.e. detects the polarity of actuation at the motor terminals. So at each manoeuvre, it checks that the connection to the motor concerned changes polarity from negative to positive for the actuation time and then returns to the GND potential. If the connection remains at Vbatt (relay with stuck contacts, accidental short circuit, etc.), the body computer then activates the other relay to bring the connections to the same potential and de-activate the current in the motors. As there is another current consumption, the body computer constantly checks the polarities and deactivates the relay if the circuit is in normal conditions.

The central locking circuit is protected by a special fuse next to the junction unit.

The system is then able to detect the state of the doors

The 'doors not shut properly' light appears on the instrument panel when one or more doors or the luggage compartment is not shut properly; moreover in this condition the 'Doors Open' message is displayed. If it is only the boot, the specific message 'Boot Open' is displayed. The instrument panel also activates the buzzer for an acoustic signal.

Body computer

is either supplied by the ignition or directly to pin 11 of connector E and to pin A connector C of the junction unit under the facia

.

There is a protective fuse

for the direct supply located in the engine compartment junction unit

.

These lines even supply the instrument panel and split inside the junction unit under the facia. The lines are protected by fuses

e

.

Pins 8 and 9 connector D of the body computer are connected to earth.

Body computer

receives control signals from the front door locks at pins 24 and 34 (release/lock) for right motor

and at pins 17 and 35 (release/lock) for left motor

.

Body computer

controls the central locking system motors, according to the system outlined above, from pins 16 and 18 of connector D in the junction unit under the facia

.

The locks communicate their opened or closed status to body computer M001 at pins:

• 8 of connector A for the left front door;
• 25 of connector A for the right front door;
• 16 of connector A for the left rear door;
• 26 of connector A for the right rear door;
• 36 of connector A from the boot switch.

In turn, via the CAN line, the body computer

informs the instrument panel

if one or several doors or the boot are not properly closed. In this case the 'doors not shut properly' warning light comes on, the message is displayed and the buzzer is activated for the acoustic signal.

The radio frequency signal

exchanges information with the body computer

concerning the commands it receives via pins 21 (earth) and 31 (command) of connector C.

The body computer then forwards commands to the locks.