GF80.20-P-0005MCU Central locking (CL), function
GF80.20-P-0005MCU Central Locking (CL), Function
1 Unlocking/locking request
2 Doors status
3 Rear-end door status
4 Unlocking and locking actuation
5 Visual feedback actuation
6 Rear-end door unlocking request
7 Rear-end door unlocking actuation
8 Interior locking or unlocking request
9 Door unlocked via inside door opener
10 Crash signal
11 Rear-end door upper section opening request (on model 451.3)
12 Emergency unlocking request via door lock
13 Vehicle speed
A1 Instrument cluster
E1e5 Left turn signal lamp
E2e5 Right turn signal lamp
E3e11 Left brake/turn signal light
E4e11 Right brake/turn signal light
E22/1 Left additional turn signal lamp
E22/2 Right additional turn signal lamp
M14/5 Right door CL [ZV] motor
M14/5s1 Right door CL [ZV] microswitch
M14/6 Left door CL [ZV] motor
M14/6s1 Left door CL [ZV] microswitch
M14/7 Rear-end door CL [ZV] motor
M14/10 Fuel filler flap CL [ZV] motor
N2/7 Restraint systems control unit
N10/10 SAM control unit
S6/1 Cockpit switch group
S6/1s11 Inside unlock CL [ZV] switch
S6/1s12 Inside lock CL [ZV] switch
S15 Remote trunk opening switch (on model 451.3)
S17/8 Trunk lid rotary tumbler microswitch (on model 451.4)
S87/6 Right door rotary tumbler microswitch
S87/7 Left door rotary tumbler microswitch
S88/9 Tailgate handle switch
A Transmitter key
CAN Controller Area Network (data bus/CAN bus) (CAN)
Function
The vehicle doors, rear-end door and fuel filler flap, as well as separate opening of the rear-end door upper section, are locked and unlocked by the central locking (on model 451.3).
The SAM control unit is the master control unit for these functions.
Manual functions
The central locking is operated by:
^ Locking/Unlocking via transmitter key
^ Locking via inner lock CL switch
^ Unlocking via inner lock CL switch
^ Locking via inside door opener
^ Emergency operation
^ Remote trunk lid opening (on model 451.3)
Automatic functions
^ Speed-dependent locking
^ Relocking
^ Emergency opening after crash recognition
Locking via transmitter key
Function requirement
^ Vehicle doors and rear-end door closed
Function
When the lock button on the transmitter key is actuated, it transmits a radio signal to the SAM control unit. It checks the access authorization of the transmitter key. If the access authorization is valid, the opening request of the rear-end door handle switch is inhibited and the following motors are actuated directly by the SAM control unit:
^ Right door CL [ZV] motor
^ Left door CL [ZV] motor
^ Fuel filler flap CL [ZV] motor
On vehicles with code (V54) Rain/light sensor, Rain/light sensor, the parking lights and the low beams are switched on for approx. 12 s by the SAM control unit depending on the ambient brightness.
Unlocking via transmitter key
When the unlock button on the transmitter key is actuated, it transmits a radio signal to the SAM control unit.
The SAM control unit checks the access authorization of the transmitter key. If the access authorization is valid, the vehicle is unlocked selectively. For this purpose, the following motors are actuated directly by the SAM control unit:
^ Left door CL [ZV] motor
^ Fuel filler flap CL [ZV] motor
When the unlock button on the transmitter key is reactuated, the vehicle is unlocked globally.
For this purpose, the following motor is actuated directly by the SAM control unit:
^ Right door CL [ZV] motor
Moreover, the opening request from the rear-end door handle switch is enabled. The status of the rear-end door handle switch is read in directly by the SAM control unit, which actuates the trunk lid CL motor.
If the vehicle is unlocked selectively, the SAM control unit fades on the interior illumination. On vehicles with code (V54) Rain/light sensor, the parking lights and the low beams are switched on for approx. 12 s by the SAM control unit depending on the ambient brightness.
Visual feedback
After locking or unlocking, the turn signal lights, as well as additional turn signal lamps, are actuated directly by the SAM control unit.
^ Locking: Flashing three times
^ Unlocking: Flashing once
When the vehicle is locked, the LED in the inner lock CL switch flashes.
Locking via inner lock CL switch Function requirement
^ Vehicle doors and rear-end door closed
The locking request is read in directly by the SAM control unit via the inner lock CL switch in the cockpit switch group. This inhibits the opening request of the rear-end door handle switch and actuates the following central locking motors:
^ Right door CL [ZV] motor
^ Left door CL [ZV] motor
^ Fuel filler flap CL [ZV] motor
Visual feedback
^ When the vehicle is locked and circuit 15 ON, the LED comes on in the inner lock switch.
^ When the vehicle is locked and circuit 15 OFF, the LED flashes in the inner lock switch.
Unlocking via inner lock CL switch
The unlocking request is read in directly by the SAM control unit via the inner lock CL switch in the cockpit switch group. This enables the opening request from the rear-end door handle switch and actuates the following central locking motors:
^ Right door CL [ZV] motor
^ Left door CL [ZV] motor
^ Fuel filler flap CL [ZV] motor
Unlocking via inside door opener
When the vehicle is opened manually with the inside door opener, the door status is relayed to SAM control unit via the door rotary tumbler microswitch and the door CL microswitch. It then actuates the fuel filler flap CL motor.
The other door remains locked, the opening request from the rear- end door handle switch remains inhibited.
Emergency operation Lock
When the driver door is open, circuit 15 ON and the inner lock CL switch actuated, the vehicle is locked after circuit 15 OFF and when the driver door is closed.
If the vehicle is locked with the emergency operation, an acoustic feedback is transmitted to the warning sound generator integrated into the instrument cluster after circuit 15 OFF and removal of the transmitter key.
Unlock
The vehicle can be unlocked selectively by actuating the lock cylinder in the driver door using the transmitter key. In this case, the driver door and fuel filler flap are unlocked.
The opening request is read in by the left door CL microswitch and is relayed to the SAM control unit, which actuates the left door CL motor and fuel filler flap CL motor.
On vehicles with code (V01) Anti-theft alarm system (FFO), an alarm is triggered when a door is opened. This alarm is deactivated with circuit 15 ON.
Remote trunk lid opening (on model 451.3)
When the "Open rear-end door upper section" button is actuated on the transmitter key, it transmits a radio signal to the SAM control unit, which checks the access authorization of the transmitter key. If the access authorization is valid, it directly actuates the trunk lid CL motor, which releases the trunk lid rotary tumbler.
Speed-dependent locking
The vehicle doors are locked automatically starting at a vehicle speed of 8 km/h. The function can be activated or deactivated.
Activate
^ Circuit 15 Off
^ Simultaneously actuating inner lock CL switch and lock button on transmitter key
Deactivate
^ Circuit 15 Off
^ Simultaneously actuate inner lock CL switch and lock button on transmitter key
The doors can be unlocked via the inside door openers or the inner lock CL switch.
Relocking
The relocking function locks the vehicle automatically after 60 s, if the doors are not opened after unlocking using the transmitter key. Relock is confirmed by optical feedback
Emergency opening after crash recognition
The emergency opening function unlocks the doors of the vehicle after an accident. The crash signal is relayed by the restraint systems control unit to the SAM control unit, which actuates the left CL motor and the right CL motor.
The emergency opening function overrides all other central locking functions.
