Soft Top Operation, Detailed Description
Soft Top Operation, Detailed Description
Hydraulic System
1. Solenoid valve 1 (green)
2. Solenoid valve 2 (blue)
3. Solenoid valve 3 (orange)
4. Valve block with relief valves and shunt valves
5. Hydraulic pump
6. Oil reservoir
7. Electric motor
The hydraulic unit is located in the right-hand side of the luggage compartment. The system comprises also of two main hydraulic cylinders, which operate the soft top, two hydraulic cylinders to operate the sixth bow, two hydraulic cylinders for the soft top cover and one hydraulic cylinder to lock the soft top to the windscreen frame.
The hydraulic unit comprises a pump block with two pressure reduction valves (for clockwise or anticlockwise), two logic shunt valves (XOR valves) and three solenoid valves, 1, 2 and 3. Component locations.
The three electro-hydraulic valves are functionally identical and they are used to control the flow of oil to the hydraulic cylinders.
The fluid reservoir with level indications on the side is attached to the pump block with a hose clip. Observe that only fluid with part no. (16) 89 96 860 Power steering fluid Pentosin CHF-11S may be used.
Pump unit
The pump unit comprises a 4-cylinder piston pump which is driven by an electric motor. The motor rotation direction is controlled by STC. The hydraulic cylinders work with differential pressure in certain cases, i.e. the same pressure operates in the system but due to the piston rod taking up part of the area the pressure has a smaller area to operate in at the piston rod side. The result of this is that the piston is pushed out faster but with less force.
The soft top hydraulic cylinders for the sixth bow and soft top cover are operated anticlockwise.
Valves
The pressure is reduced by two pressure reducing valves (for rotation anticlockwise and clockwise) to 140 ± 10 bar. These reducing valves are situated after the respective delivery sides and lead fluid back to the suction side. Meanwhile, the connection between the delivery side and the fluid reservoir is closed.
The valve block, containing three solenoid valves and two shunt valves, is connected to the pump block.
Each of the three solenoid valves has three fluid connections:
^ Fluid pressure from pump
^ Fluid pressure to main cylinder
^ Oil return to reservoir
The valves have two positions: "Active" and "Rest". When a valve is active, the pressure from the pump is connected to the pressure for the cylinder in question. When a valve is at rest, the pressure for the cylinder is connected to the fluid return line to the reservoir. The valves may be activated by STC.
Hydraulic functions for opening soft top
Component locations
1. Solenoid valve 1 (green)
2. Solenoid valve 2 (blue)
3. Solenoid valve 3 (orange)
4. Shunt valve
5. Hydraulic pump with electric motor
6. Pressure reducing valve (clockwise)
7. Pressure reducing valve (anticlockwise)
8. Hydraulic cylinder, first bow/windscreen frame
9. Main hydraulic cylinder, LH
10. Main hydraulic cylinder, RH
11. Hydraulic cylinder, sixth bow left
12. Hydraulic cylinder, sixth bow right
13. Soft top cover hydraulic cylinder, right
14. Soft top cover hydraulic cylinder, left
15. Oil reservoir
16. Position sensor
17. Shunt valve
Soft Top Sequences, Opening The Soft Top, Hydraulic Functions
1. Unlocking and opening the sixth bow
When the soft top control button on the switch panel is held down, the STC control module receives a command to open the top. STC (Soft Top Control) starts the hydraulic pump (5) to the left (anticlockwise). The shunt valve (4) is opened and supplies oil to the right side of the hydraulic pump. At the same time, the connection between the left side of the pump and the oil reservoir is closed. STC activates the solenoid valves (2) and (3). This establishes the pressure connection between the hydraulic pump (5) and hydraulic cylinders (11) and (12) for the sixth bow. The sixth bow's cylinders (11) and (12) are operated to the open position, unlock and open the sixth bow.
2. Unlocking the first bow and opening the soft top cover
The hydraulic pump (5) runs anticlockwise, valves (1), (2) and (3) are activated. This means that hydraulic cylinder (8) used for locking the first bow and the hydraulic cylinders (13) and (14) for the soft top cover are opened. The first bow latch is released and the soft top cover is opened.
3. Sixth bow, intermediate position
STC activates the solenoid valves (1) and (3). The pump runs clockwise and hydraulic cylinders (11) and (12) for the sixth bow are operated to closed position and the sixth bow has assumed an intermediate position.
4. Lowering the soft top
Once the sixth bow has reached its intermediate position, the STC will activate the solenoid valves (1) and (2), thereby connecting the pressure from the hydraulic pump (5) to the main hydraulic cylinders (9) and (10). The main hydraulic cylinder pistons are retracted to lower the soft top into the soft top storage.
5. Locking the soft top cover
The hydraulic pump (5) runs anticlockwise and solenoid valve (2) is activated. Via the valve, hydraulic cylinder (8) is operated to lock the first bow and the two hydraulic cylinders (13) and (14) for the soft top cover.
All of these cylinders return to closed position. The first bow is secured and the soft top cover closes and is locked.
Soft Top Sequences, Closing The Soft Top, Hydraulic Functions
1. Opening the soft top cover
STC receives information from the soft top switch to close the soft top. Hydraulic pump (5) runs anticlockwise, solenoid valves (1) and (2) are activated, thereby opening the latch (8) for bow one and the hydraulic cylinders (13) and (14) for the soft top cover. The latch for bow one is released and the soft top cover opens.
2. Raising the soft top
Hydraulic pump (5) runs anticlockwise, solenoid valves (1) and (3) are activated, thereby connecting the pressure from the hydraulic pump to the main cylinders (9) and (10), which press out the pistons and raise the soft top.
3. Opening the sixth bow
Solenoid valves (1), (2) and (3) are activated by running the hydraulic pump (5) anticlockwise. This gives a pressure connection between the hydraulic pump and the hydraulic cylinders (11) and (12) for the sixth bow. The hydraulic cylinders for bow six are moved to open position, which opens the sixth bow.
4. Locking bow one and closing the soft top cover
The hydraulic pump (5) runs anticlockwise, solenoid valves (2) and (3) are activated. Via these, hydraulic cylinder (8) is operated for locking the first bow and the two hydraulic cylinders (13) and (14) for the soft top cover. All of these cylinders return to closed position. Bow one locking is secured and the soft top cover closes.
5. Closing the sixth bow
The hydraulic pump (5) in this case is run in the opposite direction, i.e. clockwise, which connects pressure to the main cylinders (11) and (12). Solenoid valve (3) is activated to maintain the pressure in the main hydraulic cylinders (9) and (10). The hydraulic cylinders for the sixth bow return to their original positions and the sixth bow closes.
The hydraulic system uses the following valve combinations to perform the soft top sequences:
Electro-Hydraulic System
The position the soft top is in is detected by sensors integrated in the hydraulic system, soft top mechanism and windscreen frame. Information from each sensor is received by the STC. The soft top is controlled sequentially, which means that each soft top movement must be completed before the next one can start.
The soft top opens in the following steps:
^ Sixth bow opens
^ The first bow is unlocked and the soft top cover opens
^ Sixth bow lowered
^ Soft top lowered
^ Soft top cover latches
Soft top closes in reverse order.
STC, which controls the pump and the valves, must receive confirmation of the different movements from sensors and switches within a certain time period. When one such condition is not fulfilled, all movement will cease and STC will generate an error message sent via the bus and shown on SID (Saab Information Display), e.g. "CHECK SOFT TOP".
STC also used bus messages from other control modules. If the information does not correspond to default values, STC will no allow the soft top to be operated. STC then sends an error message on the bus that is shown on SID (Saab Information Display), e.g. "Battery voltage too low".
The automatic soft top operation is carried out sequentially and is described in the following tables. The movements will be carried out after pressing the soft top button. Soft top movement is controlled by the STC control module (Soft Top Controller).
Conditions for soft top operation
^ Ignition key ON
When the ignition is ON, the soft top can be operated using the switch. If the ignition switch is turned to ST while the soft top is being operated, the soft top movement will be stopped and must be reactivated.
^ Vehicle speed below 30 km/h
The control module receives messages on the speed of the car via the I-bus. It is only possible to operate the soft top when the speed of the car is lower than 30 km/h. Otherwise the movement is stopped. The speed limiter is programmable with the diagnostic tool between 0 and 30 km/h.
^ Soft top storage lowered (applies only to opening the soft top)
The control module receives information on the soft top storage position from the position sensor. If the soft top storage is folded when an attempt is made to open the soft top, the soft top operation will be stopped and the message "CHECK SOFT TOP STORAGE" shown on SID.
^ Boot lid closed
The control module receives information that the boot lid is closed via the I-bus. If the boot lid is open and an attempt is made to operate the soft top, its operation will be stopped and the message "CLOSE TRUNK LID" shown on SID. The boot lid must be closed or it will collide with the soft top cover when it is opened.
^ Power supply to control module between 9-16V
The power supply to the control module must be between 9-16V for the control module to be able to operate the soft top or the windows.
^ Temperature, pump motor
The soft top pump motor must not be overheated. The STC system is capable of operating the soft top in 3 minutes which is equivalent to six to seven opening and closing sequences respectively in succession. The cooling off period is twice as long as the total operating time. The soft top can always be closed irrespective of the pump motor temperature.
^ Temperature above -5 degrees C
The soft top can be damaged if it is operated in under -5 degrees CC. The soft top is locked with the first press of the button and the following SID message is displayed: "Soft top can be damaged when operated in temperatures below zero". If the button is pressed again within 50 seconds the soft top can be operated. The soft top can always be closed irrespective of the temperature.
^ Roll bars must not be activated.
Sensors in the mechanism for the roll-over bars detect the position.
^ All the control module inputs/outputs are valid
The system performs a self-test every time the ignition switch is turned to ON.
Soft top sequences, opening the soft top, sensor inputs
The illustrations and the hydraulic circuit diagram describe the movements of the soft top during raising and retracting. The tables describe the status of the position sensors with respect to each movement sequence. The outputs are marked in italics and the inputs are underlined in the table headings. For changes of status, the read values are marked in bold.
Supervision time. Each of the movements (soft top, bow and cover) has a maximum allowed time (supervision time). STC controls each of the movements so that none of them exceed their respective supervision times. If the time is exceeded, the hydraulic system will immediately switch to stop mode. Automatic operation can be restarted by releasing the button "Close soft top" or "Open soft top" and then pressing the relevant button again.
The diagnostic tool can be used to read the status of each position sensor.
Description of position sensor status:
On Active input
Off Input inactive
On/Off Input in transition mode
1. Status of position sensors prior to activation when the soft top is closed.
2. Step 1, unlocking and opening of sixth bow.
When activating the soft top button, the control module performs the following:
3. Step 2, releasing first bow and opening soft top cover.
4. Step 3, sixth bow, intermediate position.
5. Step 4, lowering the soft top.
6. Step 5, locking the soft top cover.
7. Status of position sensors prior to activation when the soft top is open.
Soft top sequences, closing the soft top, sensor inputs
1. Status of position sensors prior to activation when the soft top is open.
2. Step 1, opening the soft top cover.
3. Step 2, raising the soft top.
4. Step 3, opening the sixth bow
5. Step 4, locking the first bow and closing the soft top cover.
6. Step 5, closing the sixth bow
7. Status of position sensors when soft top is closed.
Window Operation, Opening The Soft Top
1. When the button for soft top operation is pressed, STC opens the soft top provided the conditions for soft top operation are approved.
2. When the soft top is down and the cover is closed. The bus message "soft top status" is changed from lower sequence to "open". MIU indicates such with an audible signal.
3. If the button for soft top operation is held in STC will send the bus messages "Request to move front windows", "Automatic opening" and "Request to move rear windows", "Automatic opening". The windows are operated by each respective door module to their lowest positions.
There is no difference between cars with pinch protection and those without.
Window Operation, Closing The Soft Top
1. Pressing the soft top button will send a Soft top operation close bus message from ICM.
2. STC closes the soft top if the conditions for operating the soft top are fulfilled.
3. When the soft top is fully closed, STC transmits the bus message "Closed". MIU will indicate such with an audible signal.
4. If the button for soft top operation is held in STC will send the bus messages "Request to move front windows", "closing" and "Request to move rear windows", "closing".
SID, text messages
The following messages are included in the soft top system and can be shown on SID together with an acoustic signal.
