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Central locking (CL), function - GF80.20-P-0005CW

MODEL 204.0/2 up to Model Year 8 

General information 

The central locking (CL) controls electric locking and unlocking of the vehicle doors, fuel filler flap and trunk lid (model 204.0) or tailgate (model 204.2).

The following controls are available:

The CL comprises the following partial functions:

Further partial functions are described in separate documents:

Function sequence for emergency opening in event of crash 

The emergency opening function unlocks the doors of the vehicle after an accident. The supplemental restraint system control unit (N2/10) transmits a corresponding message to the electronic ignition switch control unit (N73) with chassis CAN. After a waiting time of t = 8 to 11 s, the doors are unlocked.

IMPORTANT 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 locking trunk lid 

By turning the lock cylinder on the trunk lid with the emergency key, the trunk lid contact switch (S88/6) is actuated. This signal reads in the rear SAM control unit with fuse and relay module (N10/2) and inhibits opening requests from the other control points.

Function sequence for later closing trunk or tailgate 

If the trunk lid or the tailgate is closed later, this is recognized by the trunk lid rotary tumbler switch (M14/7s1) (model 204.0) or tailgate rotary tumbler switch (M147/s1) (model 204.2). The status is transmitted by the rear SAM control unit with interior CAN. The electronic ignition switch control unit then checks, whether all doors are closed. If this is the case, the trunk lid or tailgate is locked, which is indicated by a visual feedback signal.

Function requirements for additional door lock 

Function sequence for additional door lock 

When locking the CL, the mechanical interior actuation feature is switched off, so that the doors can no longer be opened from the inside. This prevents breaking in into the vehicle by smashing in a window and opening a door from inside.

When the CL is locked, the electronic ignition switch control unit additionally transmits the command "Additional locking" to the left front door control unit (N69/1), right front door control unit (N69/2), left rear door control unit (N69/3) and right rear door control unit (N69/4) with the interior CAN.

The corresponding door control unit actuates the corresponding additional door lock actuator motor (A85m4, A85/1m4, A85/3m4 and A85/4m4) when locking.

Function sequence for play protection 

Each actuation of the CL 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 actuation requests for the CL are not performed. Only if the value is not reached, it is possible to reactuate the CL.

Central locking (CL), location of components GF80.20-P-0005-01CW 
Central locking (CL), block diagram GF80.20-P-0005-10CW 
Operating central locking with transmitter key, function GF80.20-P-2002CW 
Locking/unlocking vehicle with inside switch, function GF80.20-P-3009CW 
Automatic locking, function GF80.20-P-4009CW 
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