Basic Opening/Closing Soft Top Function - GF77.30-P-9900A

Model all (CAR) 

Overview 

This document contains information on:

• General 
  • Control points 
  • Emergency operation 

• Function requirements 
• Function 
  • Function sequence for manually opening/closing trunk separator 
  • Function sequence for stop mode 
  • Function sequence for overload protection 
  • Function sequence for centrally closing side window 
  • Function sequence for displaying control and warning messages 
  • Function sequence for extending/retracting wind deflector and draft stop 

General 

The soft top is operated electrohydraulically by actuating hydraulic cylinders.

An electric motor in the soft top control hydraulic unit actuates a hydraulic pump, which generates the required operating pressure. The hydraulic cylinders are controlled by the rear control unit through solenoid valves in the soft top control hydraulic unit.

Several hydraulic cylinders are installed, the soft top bow hydraulic cylinder (raise/lower), the soft top compartment cover hydraulic cylinder (open/close) and the soft top operation hydraulic cylinder. Multiple limit switches are installed. They monitor the position of the soft top, soft top bow, soft top compartment lid and soft top lock. The status of the limit switch is read in directly by the rear control unit.

Control points: 

• Soft top control switch
• Transmitter key (convenience opening/closing function)

Emergency actuation: 

The soft top can be manually (by hand) opened and closed. Close soft top manually:

• Open side window.
• Bleed pressure in hydraulic unit using Allen wrench (included in Operator's Manual pouch).
• Fold down hinges of soft top compartment and pull through straps (contained in vehicle tool kit).
• Close trunk lid.
• Close and lock soft top.

Manually open soft top:

• Pull soft top compartment lid using straps to rear, until the vertical end stop is reached.
• Route soft top out of soft top compartment and place onto windshield frame.
• Remove cap from Allen screw in headliner.
• Turn valve clockwise using Allen wrench up to end stop, and then turn in counterclockwise direction.
• Position soft top bow in vertical position and lower soft top compartment lid.
• Press soft top bow downward until it arrests.

The soft top control comprises the following partial functions:

• Opening/closing soft top
• Automatically opening/closing trunk separator (vehicles with automatic remaining luggage compartment separator)
• Stop mode
• Overload protection
• Automatic closing of side windows
• Displaying control and warning messages
• Extend/retract wind deflector and draft stop (vehicles with draft stop for convertible)

Function requirements 

• Transport mode not activated
• No overvoltage or undervoltage
• No engine start (circuit 50 Off)
• Circuit 15 ON (for control point switch for soft top control)
• Soft top in defined position
• Trunk lid closed
• Luggage compartment separation closed
• Speed below 40 km/h
• Roll bar not triggered

When the transport mode is activated, the closed soft top cannot be opened.

The electronic ignition lock control unit transmits the status of circuit 15 and circuit 50 to the rear control unit.

The position of the soft top is sensed by evaluating the status of all limit switches. The rear control unit directly reads in the status of all limit switches.

The status of the trunk lid (open or closed) is sensed by the trunk lock main catch switch in the trunk lock. The rear SAM control unit reads in the status of the trunk lock main catch switch directly and sends this to the rear control unit.

The rear control unit directly reads in the signals of the trunk separator Hall sensors.

The instrument cluster control unit transmits the vehicle speed to the rear control unit via the electronic ignition lock control unit. The supplemental restraint system (SRS) control unit transmits the status of the roll bar to the rear control unit via the electronic ignition lock control unit.

Function 

When the soft top control switch is actuated, the soft top is opened or closed manually for the time the request is present. The rear control unit directly reads in the status of the soft top control switch.

When the "Comfort opening/closing" function is actuated using the transmitter key, the soft top is opened or closed as long as the request is pending.

Function requirements for opening/closing soft top:

• No engine start (circuit 50 Off)
• Circuit 15 ON (for control point switch for soft top control)
• Soft top in defined position
• Trunk lid closed
• Speed v < 40 km/h
• Roll bar not triggered

Function sequence for manually opening/closing trunk separator 

The trunk separator can be opened or closed manually by actuating the trunk separator switch. The rear control unit reads in the status of the trunk separator switch directly and actuates the trunk separator motor according to the actuation.

Function requirements for manually opening/closing trunk separator:

• Trunk lid opened
• Soft top closed and locked (to open trunk separator)

Function sequence for stop mode 

If the opening or closing procedure of the soft top is interrupted due to erroneous or missing input factors, the rear control unit activates the stop mode. During the stop mode the solenoid valves for the soft top control hydraulic unit are actuated so that the motion of the soft top is stopped. The soft top is arrested. When the opening or closing procedure of the soft top is enabled and a new actuation request is present, it is restarted or continued.

Function requirements for stop mode:

• Soft top not in locked end position

If a solenoid valve responsible for stop mode function is defective, the stop mode is not started.

Function sequence for overload protection 

The soft top can be opened or closed in either direction as long as the hydraulic fluid temperature does not exceed T = 85°C. The temperature sensor in the soft top control hydraulic unit actuates the overload protection of the soft top control hydraulic unit electric motor. The rear control unit directly reads in the signal from the temperature sensor and calculates the hydraulic oil temperature.

Function sequence for centrally closing side window 

All side windows can be closed from one control unit via the power window central operation switch.

If the power window central operation switch is actuated to the first catch, the power window motors are actuated for the time the actuation is in progress. The side windows are closed. When the power window central operation switch is actuated beyond the first catch, the power window motors are actuated until the side windows are completely closed.

The rear control unit reads the status of the "power window assembly central operation" switch directly and sends the information "convenience feature mode" and "convenience feature direction" to the front door control units. The front door control units then actuate the front power window motors. The rear door control unit directly actuates the rear power window motors.

Function requirements for central closing of side windows:

• Terminal 15 R on

The electronic ignition lock control unit transmits the circuit 15 status to the rear control unit.

Function sequence for displaying control and warning messages 

The rear control unit evaluates the functional capability of the soft top control continuously.

Malfunctions are displayed in the instrument cluster control unit. For this purpose, the rear control unit transmits the corresponding information via the electronic ignition lock control unit to the instrument cluster control unit.

The message is displayed regardless of the circuit status of circuit 15. Also during comfort opening/closing of the soft top.

Individual messages can be transmitted parallel to other messages. Otherwise, the rear control unit transmits only one message to the instrument cluster control unit with the corresponding priority. Messages with same priority cannot be present simultaneously due to the soft top motion sequence.

Function sequence for extending/retracting wind deflector and draft stop 

When using the wind deflector and draft stop, the air swirl (draft) in the vehicle interior is reduced.

Retracting and extending the wind deflector and draft stop, can be operated over the draft stop and wind deflector button in the soft top control switch.

The rear control unit reads in the status of the draft stop and wind deflector button directly, and actuates the draft stop actuator motor accordingly. Beginning with a speed of v > 40 km/h the wind deflector above the windshield also extends. At a speed of v < 15 km/h, the wind deflector retracts automatically. The rear control unit actuates the wind deflector actuator motor.

The position of the draft stop and the wind deflector is monitored by the limit switch, which is integrated in the corresponding actuator motor. The rear control unit directly reads in the signals of the limit switches. The status of the wind deflector and draft stop (extended or retracted) is signaled to the driver by two status LEDs in the draft stop and wind deflector button, which are directly actuated by the rear control unit. If the wind deflector and draft stop have been extended and circuit 15 C is then switched off, the wind deflector and draft stop will retract again (component protection). After switching on circuit 15, the wind deflector and draft stop is extended. If the draft stop and wind deflector button is actuated shortly after circuit 15 C is switched off, the wind deflector and draft stop will extend again.

Additional function requirements for extend/retract wind deflector and draft stop:

• Circuit 15 ON
• Soft top completely open
• Speed v < 160 km/h (for operation)

Extending or retracting the wind deflector above the windshield and the draft stop is possible up to a speed of v < 160 km/h. Above this speed threshold, the wind deflector and the draft stop remain in the previous position.

The electronic ignition lock control unit transmits the circuit 15 status to the rear control unit.

The instrument cluster control unit sends information on vehicle speed to the rear control unit.

For cleaning the wind deflector can be extended when the soft top is closed. For this purpose the parking brake must be applied. Then the net of the wind deflector can be cleaned.

If a seat belt is applied in the rear, the draft stop moves to the uppermost position.

Function requirements for extending/retracting the wind deflector and draft stop

• Circuit 15 ON
• Soft top completely open
• Speed v < 160 km/h (for operation)

	Function schematics
	Function schematic for opening/closing soft top	Model 238 as of model year 2021	PE77.30-P-2500-97A
		Model 232	PE77.30-P-2500-97B
	Additional basic functions
	Basic trunk separator function		GF77.38-P-9900A
	Soft top basic hydraulic unit function		GF77.30-P-9901A