Opening trunk lid with transmitter key function - GF80.20-P-3010B

MODELS 215, 220 with CODE (881b) Remote trunk locking (RTL) 

Fig 1: Identifying Transmitter Key

Operating procedure 

If the "Open trunk lid" push-button is operated the transmitter key (A8/1)  sends a radio signal to the rear window antenna (A2/32) in the vehicle. From there the radio signal is sent by the rear window antenna amplifier module (A2/12) to the overhead control panel control module (N70). The trunk lid opening information is sent from the overhead control panel control module (N70) to the EIS control module (N73)  over the CAN. The EIS control module (N73) checks the access authorization of the transmitter key. If access authorization is issued, the EIS control module (N73) sends the command to open the trunk lid over the CAN to the pneumatic control module (combined) (A37)  .

If the trunk lid was not mechanically locked using the transmitter key (A8/1), the pneumatic control module (combined) (A37) activates the following functions directly one after the other:

• An increase in excess pressure in the rear lock's pneumatic cylinder to release the trunk lid.
• Activation of the hydraulic pump RTL (M51)  through driving the trunk lid open relay (K69/1). 

Thehydraulic ram  is then charged with fluid by the hydraulic pump RTL (M51) and opens the trunk lid by way of the multiple-jointed hinge to its end position.

When the trunk lid reaches the end position the trunk lid opening angle detection sensor (B24/16)  registers this and informs the pneumatic control module (combined) (A37). When the trunk lid opening angle detection sensor reaches the specified limit stop position, the pneumatic control module (combined) (A37) switches off the hydraulic pump RTL (M51) and the trunk lid stops in the open position

Operating instructions 

If the "Open trunk lid" push-button is pressed again on the transmitter key (A8/1)  the hydraulic pump RTL (M51) is immediately stopped  . The trunk lid is then held at the position that it was in. Pressing the push-button again restarts the opening operation. An interruption to the trunk lid movement can be overridden by the trunk lid release switch (S15/1) control or the remote trunk lid release switch (S20/1s6).

Safety mechanism 

With the aid of the trunk lid opening angle detection sensor (B24/16) the pneumatic control module (combined) (A37) can also initiate an emergency-stop function  . In the event that the trunk lid encounters an obstacle, or a manual intervention takes place on the trunk lid, the trunk lid opening angle detection sensor (B24/16) registers a change in speed of the trunk lid. The pneumatic control module (combined) (A37) immediately switches off the hydraulic pump RTL (M51) and the trunk lid stops at the position it was in at that time.

Manual  operation of the trunk lid is possible in an emergency, but necessitates greater physical effort as the hydraulic system also has to be moved. The trunk lid opening angle detection sensor (B24/16) does not require any recalibration after a manual intervention.