GF80.20-P-0001FL Liftgate Remote Actuation, Function

GF80.20-P-0001FL Liftgate Remote Actuation, Function

MODEL 212.2

Function requirements, general
- Terminal 30
- No overvoltage or undervoltage
- System synchronized
- Speed v = 0 km/h

The vehicle speed signal is transmitted by the instrument cluster A1) to the liftgate control unit (N121/1) via the interior CAN (CAN B).

Normalization of the rear-end door actuation should only be performed after replacing a component or after adjustment work.

Rear-end door remote actuation, general
The liftgate can be opened and closed automatically via the rear-end door actuation feature. When the driver liftgate control button (S15/3) or transmitter key (A8/1) is actuated, a liftgate control warning tone sounds twice when the liftgate (H4/60) is closed. The warning buzzer is actuated by the lift control unit.
A waning tone sounds, when the liftgate external operation switch (S88/8) or liftgate control button (S62/36) is actuated.

The rear-end door remote actuation function comprises the following partial functions:
- Function sequence for closing liftgate
- Function sequence for opening liftgate
- Function sequence for opening angle limitation
- Function sequence for lockup recognition

If the liftgate is opened or closed using any control in the rear-end door remote actuation and if this or another control element is actuated, the drive is immediately stopped. When the control is actuated again, the liftgate is moved to the opposite direction.

Function sequence for closing liftgate
Closing the liftgate comprises the following subfunctions:
- Function sequence for automatically closing via liftgate control button
- Function sequence for manually or automatically closing liftgate via driver liftgate control button
- Function sequence for automatically closing liftgate via transmitter key
- Function sequence for power closing

Function sequence for automatically closing via liftgate control button
Actuation of the liftgate control button is read by the rear SAM control unit with fuse and relay module (N10/2) and is relayed to the liftgate control unit via the interior CAN.
The liftgate control unit then actuates the liftgate control electric motor (M51/3m1) in the liftgate control drive unit (M51/3) in the closing direction.

On vehicles with code (889) Keyless Go, the central locking can also be locked depending on the actuation of the liftgate control button.

Function sequence for manually or automatically closing liftgate via driver liftgate control button
Continuously actuate driver liftgate control button to close manually. Actuate driver liftgate control button once to close automatically. Both requests are read in by the left front door control unit (N69/1) and relayed to the liftgate control unit via the interior CAN.
The liftgate control unit then actuates the liftgate control electronic motor in the closing direction.

Function sequence for automatically closing liftgate via transmitter key
When the remote rear door actuation transmit button on the transmitter key is actuated for t > 0.5 s, it transmits a radio signal to the FM 1, AM, CL and KEYLESS-GO antenna amplifier (A2/18). This signal is read in by the rear SAM control unit and relayed to the electronic ignition switch control unit (N73). The electronic ignition switch control unit checks the access authorization of the transmitter key. If it is valid, the liftgate control electric motor is actuated in the closing direction by the liftgate control unit.

Actuating the liftgate remote control unlock transmit button a second time stops the closing procedure, actuating again opens the liftgate.

Function sequence for power closing
If the rear SAM control unit recognizes that the liftgate is arrested with the liftgate rotary tumbler switch (M14/7s1), the liftgate is completely closed by the rear SAM control unit with the liftgate locking element (M14/31).

Function sequence for opening liftgate
Opening the liftgate comprises the following subfunctions:
- Function sequence for opening liftgate with liftgate external operation switch
- Function sequence for opening liftgate with driver liftgate control button
- Function sequence for opening liftgate with transmitter key

Additional function prerequisites for opening liftgate using liftgate external operation switch
- Vehicle unlocked with transmitter key or
- Transmitter key inserted into electronic ignition lock after locking with transmitter key

Function sequence for opening liftgate with liftgate external operation switch
Actuation of liftgate external operation switch is read in by the rear SAM control unit. The rear SAM control unit transmits this message to the interior CAN and simultaneously actuates the liftgate locking element to unlock the liftgate. The liftgate control unit then actuates the liftgate control electric motor in the opening direction until the liftgate control position sensor (M51/3b2) recognizes the limit stop of the liftgate.

Additional function sequence for opening liftgate with driver liftgate control button
- Vehicle unlocked with transmitter key or
- Transmitter key inserted into electronic ignition lock after locking with transmitter key

Function sequence for opening liftgate with driver liftgate control button
Actuation of the driver liftgate control button is read in by the left front door control unit and relayed to the liftgate control unit via interior CAN.
The liftgate control unit then actuates the liftgate control electric motor in the opening direction until the liftgate control position sensor recognizes the limit stop of the liftgate.

Function sequence for opening liftgate with transmitter key
When the liftgate remote door unlock transmit button on the transmitter key is pressed for t > 0.5 s, it transmits a radio signal to the rear window antenna amplifier 1.
This signal is read in by the rear SAM control unit and relayed to the electronic ignition switch control unit.
The electronic ignition switch control unit checks the access authorization of the transmitter key.
If it is valid, the liftgate control unit then actuates the liftgate control electric motor in the opening direction until the liftgate control position sensor recognizes the limit stop of the liftgate.

Actuating the liftgate remote control unlock transmit button a second time stops the closing procedure, actuating again opens the liftgate.

Function sequence for opening angle limitation
The opening angle can be limited with the liftgate control button. The limitation of the opening angle can be set as the new limit position, if required, to prevent damage to the liftgate from extending transport items (ski box, surfboard, etc.).
To adjust the limitation of the opening angle, the liftgate must be held in the desired position or moved manually to this position. If the liftgate control button is then actuated for t = 2 s, an acoustic feedback is output once with the liftgate control warning buzzer. When the liftgate is opened, it is only opened to this stored position.

It is possible to program the opening angle only up to s = 20 cm before the end stop. If the liftgate is opened manually, the liftgate can be opened beyond the stored end position.

To deactivate the opening angle limitation, actuate liftgate control button for t = 2 s (any liftgate position). An acoustic feedback is output twice with the liftgate control warning buzzer.

Function sequence for lockup recognition
With the aid of the liftgate control Hall sensor (M51/3b1) the liftgate control unit recognizes blocking and reduction in speed of the liftgate. The liftgate control electric motor is reversed during closing and the liftgate is moved back to the initial position.
During opening the liftgate control electric motor is switched off and the liftgate remains in the momentary position.