GF80.20-P-0005CE Central Locking (CL (ZV)), Function

GF80.20-P-0005CE Central Locking (CL [ZV]), Function

Central locking (CL [ZV]), general
The CL controls electric locking and unlocking of the vehicle doors, trunk lid (model 204.0) or the liftgate (model 204.2/9) and the fuel filler flap.
The following controls are available:
- Transmitter key (A8/1)
- Left front door central locking interior switch (S85/5)
- Right front door central locking interior switch (S85/6)
- Trunk lid emergency opening switch (S88/10) (on model 204.0 with code (494) USA version)
- Trunk lid unlock button (S15/1) (on model 204.0)
- Driver liftgate control button (S15/3) (on model 204.2/9 with code (890) EASY-PACK liftgate)

This liftgate control function is described in a separate document.

The CL [ZV] function comprises the following partial functions:
^ Function sequence for emergency opening in event of crash
^ Function sequence for mechanical trunk lid lock (on model 204.0 with code (887) Valet Parking)
^ Function sequence subsequently closing trunk lid (model 204.0) or liftgate (model 204.2/9)
^ Function sequence for additional door lock (on model 204.0/2 for Great Britain)
^ Function sequence for play protection

Further subfunctions are described in separate documents:
^ Central locking operation with transmitter key, function
^ Locking/unlocking vehicle with inside switch, function
^ Automatic locking, function

Additional function requirements for emergency opening in event of crash
^ Vehicle locked (not locked externally)

Function sequence for emergency opening in event of crash
The emergency opening function unlocks the doors of the vehicle after an accident. If the supplemental restrain system control unit (N2/10) recognizes an accident event, it sends a corresponding signal via the vehicle CAN (CAN E) to the electronic ignition lock control unit an (N73) and to the front SAM control unit with fuse and relay module (N10/1).
Parallel to this, accident recognition is also accomplished by the crash sensor integrated into the front SAM control unit.

When an accident event is recognized, the front SAM control unit sends the "Emergency opening" request via the interior CAN (CAN B) to the following control units:
- Left front door control unit (/)N69/1
- Right front door control unit (/)N69/2
- Left rear door control unit (N69/3) (as of 1.12.09)
- Right rear door control unit (N69/4) (as of 1.12.09)

On vehicles up to 30.11.09 the central locking of the rear doors is controlled by the front SAM control unit (except vehicles for Great Britain).

After a waiting time of t = 8 to 11 s, all vehicle doors are locked. The emergency opening function overrides all other central locking functions.
When the vehicle has been locked from the outside, the emergency opening function is not active. In the event of rear end collision, the CL is unlocked without waiting time.

Function sequence for mechanical trunk lid locking
The mechanical trunk lid locking feature allows valuables to be locked in the trunk intentionally
Mechanical locking of the trunk lid is defined via the status of the trunk lid contact switch (S88/6). The trunk lid contact switch can be actuated by turning the emergency key of the trunk lid lock cylinder.
In the rear SAM control unit with fuse and relay module (N10/2), the status of the trunk lid contact switch is read in directly inhibiting the opening requests from other control points.

Additional function prerequisites for subsequent locking of trunk lid or liftgate
^ Vehicle locked
^ Trunk lid or liftgate open

Function sequence for subsequent closing of trunk lid or liftgate
When the trunk lid of liftgate is closed subsequently, the rear SAM control unit sends the status of the trunk lid rotary tumbler switch (M14/7s1) (model 204.0) or the liftgate rotary tumbler switch (M14/7s1) (model 204.2/9) to the electronic ignition lock control unit via the interior CAN. The latter then checks whether all vehicle doors are closed. If so, the electronic ignition lock control unit sends the request to output the turn signal confirmation that the vehicle is locked.

Additional function requirements for additional door lock
^ Interior protection activated (with code (882) Interior monitoring (only with ATA))
^ Function coded in front SAM control unit
^ All doors closed

Function sequence for additional door lock
The mechanical inside door handle is switched off by the additional door lock when the central locking is locked.
It is no longer possible to open the doors from the inside.
This prevents breaking in into the vehicle by smashing in a window and opening a door from inside.

Upon locking with the central locking, the electronic ignition lock control unit also sends the request "Additional locking" to the following control units, via the interior CAN:
- Left front door control unit
- Right front door control unit
- Left rear door control unit
- Right rear door control unit

The following actuator motors are then actuated:
- Left front door additional door lock actuator motor (A85m4) by left front door control unit
- Right front door additional door lock actuator motor (A85/1m4) by right front door control unit
- Left rear door additional door lock actuator motor (A85/3m4) by left rear door control unit
- Right rear door additional door lock actuator motor (A85/4m4) by right rear door control unit

The power is supplied to the rear door control units by the rear SAM control unit and also by the left rear door control unit fuse carrier (F64/1) and right rear door control unit fuse carrier (F64/2).

Function sequence for play protection
Each actuation of the CL [ZV] is counted by the electronic ignition switch control unit. Every t = 7 s one actuation is deducted from the current meter reading. The maximum number of actuations is 40.

After reaching this value, further action requests for the CL are not performed.
Actuation of the CL [ZV] again is possible only after dropping below this value again.