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

MODEL 221.0 /1, 216.3 as of model year 2009 /YoM 08 

Central locking (CL), general 

The CL electrically locks and unlocks the vehicle doors, the trunk lid and the fuel filler flap.

The following controls are available:

• Transmitter key (A8/1)
• Left interior CL [ZV] switch (S85/5)
• Right interior CL switch (S85/6)
• Trunk lid open/close switch (S20/1s6) (open trunk lid only, remaining CL remains locked)

On vehicles with code (881) Remote trunk closing (RTC), the trunk lid can be opened and closed hydraulically.

Additional information is given in the separate function description Remote trunk closing.

The CL function comprises the following partial functions:

• Function sequence for unlocking by opening a door from inside 
• Function sequence for child safety lock on rear door doors (on model 221 up to 31.5.09 without code (494) USA version and Code (460) Canada version or on model 221 as of 1.6.09) 
• Function sequence for emergency opening in event of crash 
• Function sequence for additional door lock (with code (833) Great Britain version) 

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 unlocking by opening a door from inside 

Vehicle locked by:

• Left interior actuation CL switch or right interior actuation CL switch
• Automatic locking

Function sequence for unlocking by opening a door from inside 

The doors can always be opened from the inside regardless of the status of the CL. The corresponding door lock is then unlocked.

Special case:

Globally locked vehicle locked with interior actuation CL switch or automatic function.

In this case, the vehicle is unlocked globally when the driver or passenger door is opened from inside.

Vehicles with code (833) Great Britain version:

If the CL is locked or relocked from the outside, the doors can only be opened from the inside, if the additional door lock was previously deactivated via the menu point "Vehicle" in the COMAND control unit (A40/3).

Function sequence for child safety lock on rear doors (on model 221 up to 31.5.09 without code (494) USA version and Code (460) Canada version or on model 221 as of 1.6.09) 

When the mechanical child safety lock in the rear doors is actuated, they cannot be opened from the inside.

This mechanical lockout can be overridden with the safety lever on the rear doors.

On vehicles without code (833) Great Britain version, without code (460) Canada version and without code (494) USA version disabling can be eliminated for t = 5 s by pressing the interior CL actuation switch.

while actuating the left rear child safety lock motor (A85/3m5) and right rear child safety lock motor (A85/4m5).

The left interior actuation CL switch is read in by the left front door control unit (N69/1) and the right interior actuation CL switch by the right front door control unit (N69/2)

From there the signal is transmitted via the interior CAN (CAN B) to the EIS [EZS] control unit (N73), which then transmits the command to actuate the rear child safety lock motors to the left rear door control unit (N69/3) and right rear door control unit (N69/4).

Function sequence for emergency opening in event of crash 

The emergency opening function unlocks the doors of the vehicle after an accident. The restraint system control unit (N2/7) transmits the corresponding message to the EIS control unit.

Parallel to this, the crash signal is transmitted to the central gateway control unit (N93), which relays the signal to the following control unit via the interior CAN:

Model 221:

• Door control module front left
• Door control module front right
• Door control module rear left
• Door control module rear right

Model 216:

• Left door control unit (N69/1)
• Right door control unit (N69/2)

After a waiting time of t = 8 to 11 s, the doors are unlocked.

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.

Additional function requirement for additional door lock (with code (833) Great Britain version) 

• Interior protection activated (on vehicles with code (882) Interior monitoring (only with ATA))

Function sequence for additional door lock (with code (833) Great Britain version) 

When the vehicle is locked with the transmitter key, the mechanical interior actuation is decoupled from all doors, so that it is no longer possible to open the doors from the inside.

The interior protection and the additional door lock are deactivated via the menu point "Vehicle" in the COMAND control unit.

If the vehicle is unlocked from the outside with the transmitter key, the additional door lock is deactivated simultaneously by a command from the EIS control unit to the door control units via the interior CAN. The doors can now be opened again from the inside.

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