Convertible Top: Description and Operation
54 01 04 (077)
Fully automatic convertible top
E64
Introduction
The electrohydraulic convertible top can be opened and closed automatically. It takes approximately 20 seconds to open or close the convertible top. The top is moved by hydraulic cylinders. An electric motor engages and disengages the latching mechanism on the cowl panel . When the convertible top opens it retracts into the convertible top compartment. The convertible top compartment lid is then automatically closed.
The convertible top can be opened and closed using 2 buttons in the centre console switch cluster.
Special features of the E64 convertible top:
- The convertible top includes a standing, heated rear glass window.
- The way the convertible top is actuated by the convertible top module (CVM) has been adapted.
- The rollover protection system has been adapted.
- The shape of the convertible top has been adapted to accommodate the standing rear window. The convertible top tails off into two fins at the rear.
Benefits of the E64 convertible top:
- Heated rear window can be lowered
- Use of rear window as wind deflector, especially for rear-seat passengers
- Good ventilation when the convertible top is closed and the rear window and side windows are open
- Coupe-like design thanks to the fins and the lines of the convertible top dropping off to the rear
New for the E64 convertible top from 09/05:
- The body gateway module (KGM) supersedes the safety and gateway module (SGM).
- The door modules on the driver's side (TMFA) and front-passenger side (TMBF) are discontinued
- The body gateway module (KGM) actuates the power windows in the front doors
Brief description of components
The components that supply input signals for the electrohydraulic convertible top are as follows:
- Hall sensor for cowl panel locked and Hall sensor for cowl panel unlocked
The two Hall sensors inform the convertible top module whether the convertible top is locked or unlocked at the cowl panel.
- Hall sensor for convertible top compartment lid lock left and Hall sensor for convertible top compartment lid lock right
The two Hall sensors inform the convertible top module whether the convertible top compartment lid is locked or unlocked at the convertible top compartment.
- Hall sensor for convertible top compartment lid locked (left) and Hall sensor for convertible top compartment lid open
The two Hall sensors inform the convertible top module which the position the convertible top compartment lid is in.
- Sensor for main pillar and sensor for tensioning bar
The main pillar sensor recognises the position of the convertible top from the angle of the main pillar.
For example, the convertible top compartment is unlocked when the main pillar is at an angle of 107°.
The tensioning bar sensor supplies the position of the tensioning bar from the angle of rotation. This allows the system to identify, for example, whether the fins are sufficiently raised.
- Hall sensor for rear window lowered
This Hall sensor monitors the position of the rear window. The convertible top can only be opened or closed when the rear window has been fully lowered.
- Switch for convertible top compartment floor
The convertible top compartment floor switch informs the convertible top module whether the variable convertible top compartment is in the lowered position.
- Rear window travel sensor in rear window drive
The rear window travel sensor informs the convertible top module of the position of the rear window.
The following control units are involved in the operation of the electrohydraulic convertible top:
- CVM: Convertible top module
The convertible top module (CVM) controls all electrical and hydraulic functions of the convertible top.
The convertible top module is connected to the K-CAN.
- TMFA, TMBF: Driver's door module, front-passenger door module
>up to 09/05
The door modules (TMFA and TMBF) actuate the front power windows. Before the convertible top is opened, the 4 side windows are automatically lowered a little.
The switch block in the driver's door is connected to the driver's door module (TMFA) via a LIN bus.
The power windows can be operated at the switch block in the driver's door.
>from 09/05
The door modules are no longer fitted from 09/05. The body gateway module (KGM) actuates the front power windows. The switch block in the driver's door is connected to the body gateway module (KGM) via the LIN bus.
The power windows can be operated at the switch block in the driver's door.
- KBM: Body basic module
The body basic module (KBM) actuates the rear power windows.
Before the convertible top is opened, the 4 side windows are automatically lowered a little.
The body basic module supplies the signal that the boot lid is closed.
The power windows and the lowering rear window can be operated from the switch block in the driver's door.
- SZM: Centre console switch cluster
The buttons for opening/closing the convertible top and their control LED are located in the centre console switch cluster (SZM).
The SZM is connected to the K-CAN. The control LED is actuated by the convertible top module via the K-CAN.
- CAS: Car Access System
The Car Access System (CAS) controls the auto-remote opening of the convertible top.
The signals from the remote control are picked up by the remote control receiver and forwarded to the CAS.
Auto-remote opening/closing via the lock barrel in the driver's door:
The CAS receives the signal from the driver's door module (TMFA).
- SGM: Safety and gateway module
>up to 09/05
The safety and gateway module (SGM) is the interface between the door modules and the convertible top module. The SGM connects the byteflight, the PT-CAN and the K-CAN.
In addition, the SGM actuates the rollover protection system for the convertible. The rollover protection system is a subfunction of the "Advanced Safety Electronics" (ASE) passive safety system.
- KGM: Body gateway module
>from 09/05
The body gateway module (KGM) actuates the front power windows.The switch block in the driver's door is connected to the body gateway module (KGM) via the LIN bus.
The KGM is the gateway between the PT-CAN and the K-CAN and diagnosis wire.
- KOMBI: Instrument cluster
The instrument cluster (KOMBI) supplies the following signals:
- Ambient temperature
- Road speed (recorded by the DSC control unit via the wheel-speed sensors)
The instrument cluster displays Check-Control messages concerning the convertible top via the variable indicator lamp.
- HUD and CID: Head-up display and Central Information Display
The head-up display (HUD) uses the variable indicator lamp and the associated short text to indicate Check-Control messages relating to the convertible top.
The detailed text that accompanies the short text with the Check-Control message can be called on the Central Information Display (CID).
The following actuators are activated at the convertible top:
- Convertible top drive
There is a hydraulic cylinder at each of the left and right-hand main pillars. There is also a hydraulic cylinder on each of the left and right-hand tensioning bars for the fins.
The convertible top drive (motor with hydraulic pump and valve block) controls all movements of the convertible top via 3 pairs of cylinders.
One pair of cylinders works on each of the:
- Convertible top main pillars
- Convertible top tensioning bars (fins)
- Convertible top compartment lid
The direction of movement of the convertible top (OPEN or CLOSE) is controlled by 2 relays.
3 valves on the valve block execute the following functions:
- Raise the fins
- Lower the fins
- Open and close the convertible top compartment lid
Pressure can be applied to the hydraulic cylinders on both the piston side and the ram side. The direction of movement of the hydraulic cylinders for the main pillars depends entirely on the direction of rotation of the hydraulic pump.
- Cowl panel lock drive
The convertible top lock on the cowl panel is driven by an electric motor.
The catch hooks on the left and right are automatically locked in the cowl panel.
- Rear-window drive
The rear window is driven by an electric motor. The convertible top module actuates the rear-window drive.
The direction of movement of the rear window (lower or raise) is controlled by the convertible top module via 2 relays.
The rear window can also be operated manually using a button on the switch block in the driver's door.
System functions
The electrohydraulic convertible top comprises the following functions:
- Automatic opening and closing of the convertible top with the two buttons in the centre console switch cluster (SZM)
- Opening and closing of the convertible top with the key and opening the convertible top and the windows with the remote control
- Emergency closure of the convertible top by hand
- Lowering and raising the rear window
Automatic opening and closing of convertible top with the two buttons in the centre console switch cluster (SZM)
For automatic opening and closing of the convertible top, the following conditions must be satisfied:
- On-board supply voltage greater than 10,5 volts
- Terminal R ON
- Ambient temperature between -20 °C and +80 °C
(signal from instrument cluster)
- Boot lid closed
(signal from boot lid lock via body basic module)
- Road speed lower than 30 km/h
(signal from instrument cluster)
- Convertible top compartment lowered
(signal from convertible top compartment floor switch)
- Rear window fully lowered
(signal from rear window Hall sensor at bottom of rear-window drive)
- Power window operation enabled
(signal from Car Access System)
To automatically open or close the convertible top, the corresponding button in the centre console switch cluster must be pressed and held.
The control LED between the buttons in the centre console switch cluster lights up green to indicate that the convertible top is moving.
Automatic opening runs as follows:
- The side windows are lowered slightly (to protect the window seals).
- The rear window is lowered fully.
- The convertible top is released at the cowl panel.
- The fins and the bow strut are raised (tensioning bar cylinders are retracted)
- The convertible top compartment lid is unlocked and opened.
- The convertible top is folded away into the convertible top compartment.
- The convertible top compartment lid is closed and locked.
- The side windows and the rear window are raised once the convertible top compartment lid has been locked.
Automatic closing runs as follows:
- The side windows are lowered slightly (to protect the window seals).
- The rear window is lowered fully.
- The convertible top compartment lid is unlocked and opened.
- The convertible top is raised out of the convertible top compartment.
- The convertible top compartment lid is closed and locked.
- The fins are lowered.
- The front of the convertible top is lowered and locked onto the cowl panel.
- The side windows and the rear window are raised once the convertible top compartment lid has been locked.
The control LED in the centre console switch cluster flashes red under the following conditions:
- Movement of the convertible top is interrupted due to a malfunction
- Button not pressed (released) and the convertible top has not reached a secure end position
The control LED in the switch cluster centre console lights up red if the convertible top compartment is raised and the at the same time a button (OPEN/CLOSE) is pressed.
Check-Control messages are displayed for different malfunction causes.
Check-Control messages are displayed at the same time in the instrument cluster, the central information display and the head-up display.
Opening and closing convertible top with key; opening convertible top and windows with remote control
There are two different ways of moving the convertible top:
- Opening and closing with the key in the driver's door lock barrel
- Convenience opening with the remote control
Opening and closing with key in driver's door lock barrel
While the convertible top is moving, the key must be held in the "open" or "close" position in the lock barrel.
Auto-remote opening with remote control
While the convertible top is moving, the "Open" button on the remote control must be pressed and held.
Difference to opening with the button in the centre console switch cluster (SZM):
The side windows and rear window are lowered fully and are not raised again.
As there is no anti-trap circuit, convenience closing with the remote control is not possible.
Emergency closure of convertible top by hand
If the electro-hydraulic system should fail, the convertible top can also be closed manually.
Emergency closure runs as follows:
- Fully lower all 4 side windows slightly and the rear window.
- Release the convertible top compartment lid from inside the boot (left and right) and open the convertible top compartment lid.
- With the help of a second person, lift the convertible top out of the convertible top compartment and raise the fins.
- Close the convertible top compartment lid.
- Lower the fins down onto the convertible top compartment lid.
- Remove the cover panel in the middle of the bow strut.
- Use the offset hexagon socket (from the on-board tool kit) at the bow strut to lock the convertible top. Here, the hexagon socket is inserted into the drive for the cowl panel lock.
Lowering and raising the rear window
The convertible top module controls the automatic lowering and raising of the rear window (before and after the convertible top is opened or closed).
The rear window can also be actuated by pressing the button above the switch block in the driver's door.
It is only possible to lower or raise the rear window under the following conditions:
- Convertible top completely closed
- Convertible top completely open
The rear window is not equipped with an anti-trap circuit.
In an emergency, the rear window can be manually opened or closed:
- Remove the cover panel between the rear-seat head restraints.
- Insert the offset hexagon socket wrench (from the on-board tool kit) in the screw and move the rear window manually. Anticlockwise means close.
Notes for service staff
The following information is available for service staff:
- General note:
- Diagnosis: ---
- Encoding/programming: ---
Subject to change.