Central Locking System, Detailed Description
Central Locking System, Detailed Description
General
The BCM is the control module containing all central locking system logic. The BCM sends lock commands on the bus. Each door module activates the central locking system motor in its door, the luggage compartment lock is activated by the REC and the fuel filler flap by the BCM. The remote receiver, which is in the CIM, checks that the remote control code is approved, identifies the remote control as well as the button pressed and how it has been pressed. The CIM then wakes the other systems on the I-bus and sends out information on the bus.
TSL
Theft Security Locking (TSL) is activated when the car is locked with the remote control. TSL is not available on the US/CA market. TSL is an option on all EU cars, except for those on the SE, GB, F, B and NL markets where TSL comes as standard. TSL is an additional lock mode that prevents the doors from being unlocked from inside the car.
TSL can only be deactivated with the remote control, with the exception of the left front door that can be unlocked with the emergency key. TSL activation with a double press of the remote control lock button can be selected with the diagnostic tool. If the key is inserted in the ignition, the door locks will change status from TSL active to locked. The doors can then be unlocked from inside the car with the central locking button in the front door.
Mechanical operation
The left front door can be locked mechanically with the emergency key provided the door is closed. The emergency key can unlock the door even if it is TSL-active. All doors can be locked with the mechanical door lock knobs, but the driver's door must be closed. All doors can be unlocked in the same manner provided they are not TSL-active.
Low battery voltage
Locking with the cabin switches is blocked when battery voltage is below 9V. If the voltage drops below this level during locking, the BCM will send an unlocking command. If this is repeated 3 times during a 3-minute period, the locking attempts will be interrupted until the engine is started and the battery voltage exceeds 9V. The locks cannot be operated electrically when the starter motor is being operated.
Remote control
The remote control has the following functions:
1. Lock/Comfort closing (US/CA does not have comfort closing)
2. Unlock/Comfort opening
3. Boot lid Unlock/Open
4. Panic alarm/Halo Light. See Anti-theft alarm, Detailed description and Halo Light, detailed description.
Remote receiver
The remote control receiver is located in the CIM. The receiver is shut down when vehicle speed exceeds 5 km/h in order to avoid being affected by the tyre pressure monitoring system. The receiver is also shut down in "transport mode", i.e. when the transport fuse in the UEC is removed so that the car shall have the lowest possible standing current consumption. BCM listens to the bus messages for depressed remote control buttons from the CIM till the remote control/starter key is put in the ignition and transponder approval. The way in which a button on the remote control is pressed is identified by the CIM in accordance with the following:
^ Single press less than 2s in duration
^ Double press when pressed twice within a period of 5s
^ Continuous press lasting longer than 2s
When the remote control is used, information is transferred regarding the remote control battery status. If the level from the same remote is too low 10 consecutive times, the CIM will send a message out on the bus. A weak battery is indicated in the SID.
Key programming
Key programming is carried out using the diagnostic tool. All keys must be available for programming. Both transponder and remote control are programmed in one sequence. 5 keys can be programmed. The number of programmed keys is displayed in SID if the button for boot lid opening is pressed when the ignition key is in the ON position. The car must also be stationary. For further information see Key programming.
Locking and unlocking doors with the remote control
With TSL locking the driver's door must be closed. This also applies for US/CA which does not have the TSL function. Other doors lock and the car is then locked when these are closed. Locking or unlocking using the remote control can be confirmed with an acoustic signal and with the direction indicators (depending on market and selectable using the diagnostic tool). If the locking or unlocking does not work for any reason then no confirmation will be given. After locking with the remote control, the door buttons for the central locking system and the boot, as well as the switch in the boot lid handle, are disconnected.
Comfort closing/opening
4D, 5D
CV
The function is available on cars which have pinch protection for the window lifts and can only be activated using the remote control on condition that the ignition is off and the battery voltage is OK. Comfort closing is not available in the US/CA market.
Comfort opening opens the windows and sunroof/soft top, but the mirrors are not folded out. The function is activated using the remote control's unlock button, which is pressed and held. When opening is complete and without fault this is confirmed with the ordinary indication for unlocking.
4D, 5D: Comfort closing means that the windows are raised, the sunroof closed and the mirrors retracted (the function depends on how the car is equipped). The function is activated by pressing and holding in the remote control's lock button. When closing is complete and without fault this is confirmed with the ordinary indication for locking.
Remote control lock logic
Remote control not in the ignition switch
Remote control in the ignition
Central locking system door buttons
Both front doors have a central locking button for locking and unlocking. During locking, all doors are locked if the driver's door is closed. The switch in the boot lid handle is disengaged and the fuel filler flap locks (not US/CA). If any of the passenger doors are subsequently closed, they will remain locked. During unlocking of a car for the US/CA markets, only the door with an activated button will be unlocked with the first press of the button. When the button is pressed a second time, the other doors will be unlocked and the boot lid handle will be activated. For the other markets, all doors and the fuel filler flap will be unlocked and the boot lid handle will be activated with the first press of the button. The buttons are not active if the car is locked with the remote control.
Locking logic for boot lid
A single press of the button on the remote control opens the boot lid (pop-up). Other functions can be set using the diagnostic tool.
If the car is unlocked, the boot lid can be opened with the handle. This function can be adjusted using the diagnostic tool. On the US/CA market, the boot lid is locked even if the car has been unlocked.
US/CA: A button located in the driver's door activates the luggage compartment handle when pressed once. A double press opens the boot lid (pop up). When the door button is used to open the boot lid, it flashes three times. The button is not active if the car is locked via the remote control or if vehicle speed exceeds 13 km/h.
Automatic locking
If the boot lid or any door is not opened within 3 minutes after remote control unlocking, the fuel filler flap, all doors and the boot lid will lock (market-dependent and selectable with the diagnostic tool). At the same time, the door buttons for the central locking system, boot lid and the boot lid handle switch are disengaged. The same functionality is initiated when locking with the remote control. No light or sound confirmation is indicated when using this locking method. The switch in the boot lid handle is disengaged 30 seconds after the boot lid is closed. This results in the boot lid being locked from the outside.
Telematics
For certain markets, the central locking system can be controlled remotely via a telematic service (OnStar).
Automatic unlocking with activated airbag
If the ACM has activated the airbag then the central locking system unlocks the car after 15 seconds.