GF80.20-P-0001GM Liftgate Remote Actuation, Function
GF80.20-P-0001GM Liftgate Remote Actuation, Function
- with CODE (890) EASY-PACK liftgate
Function requirements for rear door remote actuation, general
^ Circuit 30
^ No overvoltage or undervoltage
^ System synchronized
^ Vehicle speed v = 0 km/h
^ Spare tire holder open in 90° position (on model 164 with code (849) Spare tire
Information on vehicle speed is provided to the rear-end door closing control unit (N121/1) by the instrument cluster (A1) on the interior CAN (CAN B).
The position of the spare tire holder is sensed by the spare tire carrier open switch (S151/2). The status of the spare tire carrier switch is read in by the rear SAM control unit (N10/8) and transmitted to the rear-end door closing control unit via the interior CAN.
Normalization of the rear-end door remote actuation should only be performed after replacing a component or after adjustment work on the rear-end door.
Rear-end door remote actuation function, general
The rear-end door can be opened and closed automatically via the rear-end door actuation feature. Manual operation of the rear-end door is possible, but requires increased force, since the hydraulic system also has to be moved.
The following control points are available:
- Open and close switch for liftgate, driver (S15/3)
- Transmitter key (A8/1)
- Rear-end door handle switch (S88/9)
- RWTS button (S62/26)
The rear-end door closing control unit actuates the rear-end door hydraulic pump (M51/1) according to the request. The rear-end door is then opened or closed via the hydraulic cylinder and the multiple-joint hinge.
If various requests are present simultaneously the opening/closing procedure is interrupted immediately and continued after a new request.
The system is switched off after 30 requests to protect the rear- end door hydraulic pump and the rear-end door closing system control unit against overheating.
The rear-end door remote actuation function comprises the following partial functions:
^ Function sequence for closing rear-end door
^ Function sequence for opening rear-end door
^ Function sequence for warning tone output
^ Function sequence for opening angle limitation
^ Function sequence for lockup recognition
^ Function sequence for anti-pinch protection
^ Normalization function sequence
Function sequence for closing rear-end door
The rear-end door function sequence consists of the following subfunctions:
^ Function sequence for closing rear-end door via RWTS button
^ Function sequence for closing rear-end door via rear-end door switch
^ Function sequence for closing rear-end door via transmitter key
Function sequence for closing rear-end door via RWTS button
Closing the rear-end door is requested by actuating the RWTS button.
The rear-end door closing control unit reads in the status of the RWTS button and actuates the rear-end door hydraulic pump. The rear-end door is closed via the hydraulic cylinder and the multiple- joint hinge.
When the rear-end door arrests in the catch on the rear-end door locking unit (A72) the rear-end door closing control unit switches off the rear-end door hydraulic pump.
The rear-end door locking unit then closes the rear-end door completely with the power closing feature.
On vehicles with code (889) Keyless Go, the central locking (CL) can also be locked depending on the actuation of the RWTS button.
Additional function requirements for closing rear-end door via rear-end door switch
^ Circuit 15 On
Function sequence for closing rear-end door via rear-end door switch
Closing the rear-end door is requested by actuating the rear-end door switch. The status of the rear-end door switch is read in by the left front door control unit (N69/1) and transmitted to the rear- end door closing control unit via the interior CAN. The rear-end door closing control unit actuates the rear-end door hydraulic pump. The rear-end door is closed via the hydraulic cylinder and the multiple-joint hinge. When the rear-end door arrests in the catch on the rear-end door locking unit () the rear-end door closing control unit switches off the rear-end door hydraulic pump. The rear-end door locking unit then closes the rear-end door completely with the power closing feature
Actuating the rear-end door open and close switch a second time, while the rear-end door is closing, stops the rear-end door closing procedure.
Function sequence for closing rear-end door via transmitter key
If the rear-end door button on the transmitter key is actuated for longer than t = 0.5 s a request is output to close the rear-end door. The request is transmitted by the transmitter key via radio to the roof antenna module (A2/93) and is relayed via the radio antenna interference suppression filter (A49/6) to the rear SAM control unit. The rear SAM control unit provides the request on the interior CAN. The EIS control unit (N73) read in the request and checks the authorization of the transmitter key. If the transmitter key is recognized as valid, the EIS control unit transmits a corresponding signal to the rear-end door closing control unit via the interior CAN. The rear-end door closing control unit actuates the rear-end door hydraulic pump.
The rear-end door is closed via the hydraulic cylinder and the multiple-joint hinge.
When the rear-end door arrests in the catch on the rear-end door locking unit () the rear-end door closing control unit switches off the rear-end door hydraulic pump.
The rear-end door locking unit then closes the rear-end door completely with the power closing feature.
Function sequence for opening rear-end door
The rear-end door opening function sequence consists of the following subfunctions:
^ Function sequence for opening rear-end door via rear-end door handle switch
^ Function sequence for opening rear-end door via rear-end door switch
^ Function sequence for opening rear-end door via transmitter key
Function sequence for opening rear-end door via rear-end door handle switch
Closing the rear-end door is requested by actuating the rear-end door handle switch. The rear SAM control unit directly reads in the status of the rear-end door handle switch and actuates the rear-end door locking unit to unlock the rear-end door. Then the rear SAM control unit transmits the status "Rear-end door unlocked" via the interior CAN to the rear-end door closing control unit, when then actuates the rear-end door hydraulic pump.
The rear-end door is opened via the hydraulic cylinder and the multiple-joint hinge.
The rear-end door closing control unit monitors the hydraulic operation via the opening angle recognition sensor (B24/16). As soon as the rear-end door opening angle recognition sensor reaches the determined final switch-off angle, the rear-end door closing control module switches off the rear-end door hydraulic pump.
Additional function requirements for opening rear-end door via rear-end door switch
^ Circuit 15 On
Function sequence for opening rear-end door via rear-end door switch
Opening the rear-end door is requested by actuating the rear-end door switch. The left front door control unit reads in the status of the rear-end door switch and transmits this to the rear SAM control unit and rear-end door closing control unit via the interior CAN. The rear SAM control unit actuates the rear-end door locking unit to unlock the rear-end door and transmits the status "Rear- end door unlocked" to the rear-end door closing unit via the interior CAN.
The rear-end door closing control unit then actuates the rear-end door hydraulic pump. The rear-end door is opened via the hydraulic cylinder and the multiple-joint hinge. The rear-end door closing control unit monitors the hydraulic operation via the opening angle recognition sensor. As soon as the rear-end door opening angle recognition sensor reaches the determined final switch-off angle, the rear-end door closing control module switches off the rear-end door hydraulic pump.
Actuating the driver rear-end door open and close switch a second time, while the rear-end door is closing, stops the rear-end door closing procedure,
Function sequence for opening rear-end door via transmitter key
If the rear-end door button on the transmitter key is actuated for longer than t = 0.5 s a request is output to open the rear-end door. The request is transmitted by the transmitter key via radio to the roof antenna module and is relayed via the radio antenna interference suppression filter to the rear SAM control unit. The rear SAM control unit transmits it to the interior CAN. The EIS control unit read in the request and checks the authorization of the transmitter key.
If the transmitter key is recognized as valid, the EIS control unit transmits a corresponding signal to the interior CAN. The rear SAM control unit receives this signal, actuates the rear- end door locking unit to unlock the rear-end door and transmits the status "Rear-end door unlocked" to the rear-end door closing unit via the interior CAN.
The rear-end door closing control unit then actuates the rear-end door hydraulic pump. The rear-end door is opened via the hydraulic cylinder and the multiple-joint hinge.
The rear-end door closing control unit monitors the hydraulic operation via the opening angle recognition sensor. As soon as the rear-end door opening angle recognition sensor reaches the determined final switch-off angle, the rear-end door closing control module switches off the rear-end door hydraulic pump.
Function sequence for warning tone output
When the rear-end door remote actuation is actuated, the rear-end door closing warning buzzer (H4/60) is actuated by the rear-end door closing control unit as follows:
On vehicles up to 31.8.08
An acoustic feedback is output four times via the rear-end door closing warning buzzer.
For vehicles as of 1.9.08
An acoustic feedback is output twice via the rear-end door closing warning buzzer.
Function sequence for opening angle limitation
The opening angle limitation function is intended to determine a new end position of the rear-end door (maximum opening), to prevent damage to the rear-end door by extending cargo (ski box, surfboard, etc.).
It is necessary to hold the rear-end door in the desired position to store a new end position.
If the RWTS button is actuated, a gong sounds and the new end position is stored in the rear-end door closing control unit.
To erase the stored end position, press and hold down RWTS button until the gong sound twice.
It is only possible to store or erase the end position with the RWTS button.
Function sequence for lockup recognition
The rear-end door closing control units senses with the signals from the rear-end door opening angle recognition sensor the current status and a speed change during the opening/closing procedure of the rear-end door.
If blockage is detected while closing the rear-end door, the rear end door hydraulic pump is reversed and the rear-end door is moved to the initial position.
If blockage is detected during an opening procedure, the rear-end door hydraulic pump is switched off and the rear-end door remains in the momentary position.
Function sequence for anti-pinch protection
The swivel range of the rear-end door is monitored at the side by the left rear-end door closing obstruction sensor strip (B86/1) and the right rear-end door closing obstruction sensor strip (B86/2). The signals from the obstruction sensor strips are read in and evaluated by the rear-end door closing control unit.
In addition, the evaluation includes information on the blockage detection function.
If pinching is recognized, the rear-end door hydraulic pump is reversed and the rear-end door is moved back to the initial position.
Normalization function sequence
The normalization feature serves to define the lower and upper stop for the rear-end door. Here, the rear-end door moves a certain path, until the rear-end door opening angle recognition sensor integrated into the gas-filled strut recognizes a defined switch-off angle. When the rear-end door opening angle recognition sensor recognizes that the rear-end door has made contact; this serves as the zero point for starting and as the teach-in point. Normalization is performed when for example:
- an initial startup is performed
- a system component (potentiometer, hinge or rear-end door) is replaced
- adjustment work on the replaced system component is performed
The normalization function sequence comprises the following subfunctions:
^ Function sequence for normalization of lower rear-end door stop
^ Function sequence for normalization of upper stop
Function sequence for normalization of lower rear-end door stop
Completely close rear-end door and keep closed for t = 0.5 s to learn in lower stop. The installed rear-end door opening angle recognition sensor senses the lower stop of the rear-end door. The closed position is read in by the rear-end door closing control unit.
As long as the closed position of the rear-end door is not normalized, the actively driven function of the rear-end door is not activated. After normalizing the closed position, the automatic rear- end door can be actively driven, opened and closed. However, the automatic "opening" function is only possible up to the opening limiter (garage, skibag position).
When the upper rear-end door stop is not learned in, the rear-end door overload protection or the blockage detection is not activated.
Additional function requirements for normalization upper rear- end door stop
^ Opening limiter for rear-end door in instrument cluster deactivated
^ Lower stop on rear-end door normalized
Function sequence for normalization of upper stop
The rear-end door is opened when actuating the rear-end door switch. When the rear-end door closing control unit recognizes that the end position is reached with the blockage detection, the rear-end door hydraulic pump is automatically actuated for t = 2 s without further switch actuation. The value (position) reached by the rear-end door opening angle recognition sensor is taken over as normalization value.
