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2002 CLK 320 bow lock issue.
The bow lock unlocks partially when activating soft top. It looks like there should be two steps to the bow lock unlocking, but only the first step happens. The cycle stops and I cannot lift the partially open bow without using Allen key to manually unlock top for cycle to continue. The hydrolics work fine for the rest of the cycle. Is there an adjustment at rear bow latch? Do I need a new latch?
03 SL Kleemann, 97 SL320 pano top, 95 Lorinser E320 Cabrio, Ferrari 360, Tesla X
Originally Posted by Mark Carol
2002 CLK 320 bow lock issue.
The bow lock unlocks partially when activating soft top. It looks like there should be two steps to the bow lock unlocking, but only the first step happens. The cycle stops and I cannot lift the partially open bow without using Allen key to manually unlock top for cycle to continue. The hydrolics work fine for the rest of the cycle. Is there an adjustment at rear bow latch? Do I need a new latch?
Hello Mark,
welcome to the forum! What you are describing is very unusual, if I understand the description correctly. The rear bow latches p/n 124 750 04 26 do not normally get jammed.
Can you verify that the latch has moved at all with the help of the hydraulic cylinder before you had to finish the unlatching step manually?
Has anyone "worked" on the latch or the cylinder p/n 129 800 16 72 before, or put in a part from the junkyard?
The latch does move. I can lock and unlock latch, but it will not continue the top down cycle.
The latch does partially releases but will not unlock completely.
03 SL Kleemann, 97 SL320 pano top, 95 Lorinser E320 Cabrio, Ferrari 360, Tesla X
There is only one step to the rear bow lock unlatching. You are writing that the rear bow lock moves part of the way for unlocking the rear bow, and then you have to finish unlocking with the Allen wrench/soft top tool. You are also saying that the rest of the top's cycle works fine with the hydraulic system. That rules out a hydraulic pressure problem. If you can unlock manually with the Allen wrench, then the latch is not terribly jammed, either. As I said, the rear bow latches p/n 124 750 04 26 do not normally get jammed.
That's why I have to ask again:
Has anyone "worked" on the latch or the cylinder p/n 129 800 16 72 before, or put in a part from the junkyard?
And I will add one more question:
How do you know that the rear bow lock has moved part way? (You seem to be sure about that - I just want to avoid us going through a lot of hoops if by chance the rear bow lock wasn't moving at all hydraulically and all of this is an electrical issue, so please excuse my double checking.)
When I start top down cycle I can see rear bow lift slightly. Then nothing else happens. At this point I need to shut key off and turn back on to lock bow.
If I have someone else start the top down I can "help" the bow to
release fully. At that point the top will continue thru cycle.
As far as I can tell no one has change the bow lock.
Your soft top controller is ending further operation, after the rear bow unlock operation, because it has sensed a fault. Additionally, you're able to re-lock the bow again, by turning the car off and on, because the controller reboots.
After the rear bow is unlocked hydraulically the bow should pivot up hydraulically, until in a position of approximately 90 degrees.
If the controller does not think that the rear bow did not unlock properly, further roof opening will cease. Possible anomalies could be:
I'll try to explain why, but hydraulics are above my pay grade (Klaus please feel free to chime in here). To permit operation in both directions (lock and unlock) this is a double acting differential cylinder, having pressure connections on both the rod and piston side. The sequencing of the necessary system pressures are determined / controlled by the soft top controller, via activation of solenoids in a value block (Y56), which is part of the hydraulic pump. The culprits causing the problem could be leaking internal cylinder seals or the soft top bow lock open valve (Y56/2y6).
If the soft top bow does not raise or only raises slowly, the possible culprits could be:
- Soft top bow locked limit switch (S84/16)
- Soft top bow raise valve (Y55y8)
- Faulty left or right bow cylinders (these are also differential cylinders).
I've enclosed a number of thumbnails to help with understanding the complexity of the power roof system, locate the referenced components etc..
In addition to the likely primary culprits mentioned above, there can be secondary system anomalies preventing the rear bow from unlocking or raising as well. Examples would be:
- No vehicle speed signal input to the controller
- Voltage supply to the controller (low voltage or 1 of the 3 fuses faulty)
- Soft top locked left limit switch (S84/11)
- Roll bar retracted switch (S83/5)
- Other value block malfunctions confusing the controller
- Wiring harness faults (shorts, broken wires, faulty ground returns)
- Controller lost synchronization from attempts to operate roof on low voltage
Diagnosis and repair by a qualified repair facility will most likely be $$$$$$.
However, if you have strong trouble shooting and DIY skills, the cost to repair can be 0 to $$. You'll find a lot of help from the veterans here and Top Hydraulics can rebuild all the hydraulic components. There are numerous existing threads that will bare this out.
Should you want to tackle it yourself, you might start with some basics.
- Level of pump fluid is correct.
- All 3 fuses OK
- If the pressure relief screw was turned to reduce pressure, it's turned back to maximum
Note: Your current issue coincides with the first power roof hydraulic operation
- Re-Synchronize all the limit/position limits by fully opening and closing the roof manually
Thereafter, getting the trouble code print out from the MB STAR Diagnostic System might be a good investment. If you do this, have the tech clear any of the stored fault codes (sometimes this alone restores roof operation).
Serendipity,
Thank you for your detailed reply. I believe Lock cylinder is the culprit is the culprit.
Is there anyway to test to see if I have a internal leak in that cylinder?
The top operates normally after I manually disengage from bow lock. So I believe all hydrolics are working properly.
Yes, the cylinder can be tested for an internal leak.
However, it requires specialized equipment (pressure value, fittings, plugs), procedure (reducing system pressure, which port to measure and plug, independently operating the pump) and knowledge (correct expected test pressure value), all of which is well above the DIY pay grade.
Although as mentioned above, while there can be a number of reasons your rear bow is not unlocking fully, your hunch may be correct.
FWIW, of the 7 hydraulic cylinders, the rear bow and case cover cylinders fail the most often. See page 5 at:
That's because the seals MB used have a service life of about 10 years, which varies due to heat exposure etc..
You can't see an internal leak, but if an internal seal is failing, the external seals aren't very far behind. You might want to remove the case cover carpet, which is not difficult and described on page 16, inspect the cylinder to see if other seals have begun leaking.
I believe I have the rear bow moving freely now, but the light on roll bar is now on. I believe this is interrupting the sequence of the top down operation. The Windows go down then the soft top button flashes fast. I have confirmed the trunk and soft top cover in trunk are in closed. I've tried to reset roll bar by raising to top and holding for 10 seconds. Then lowering till I hear a click (15seconds or so).
The roll bar does not go done as it should when soft top is activated.
Any ideas?
As a matter of fact I have the same issue as the thread starter. 2000 CLK 230.
I know the thread is a few years old!
I had a fuse problem a few days ago. After that the bow lock unlocked only partially when activating the soft top. It comes out a few inches, is unlocked but stays in that position. Normally it comes out a few inches more. After that the light of the roof activation switch is flashing.
I made a few trials and found out: when moving the ignition off and then to on again and then pulling the avtivationswith to open, the bow is moving further up in the 90° position. Then the cover is opening and the roof is then moving in an up position of about 90° and stopping there. It does not move any further. After recycling the ignition again I can only close the roof with the normal procedure.
I think the hydraulics is working fine but there is a false step in the opening routine.
I have a read out error of B1650-00 and an Error of 1010-000 which means that there is a current problem.
After a lot of trys (moving it manually as well), the complete cycle was working fine including the opening of the bow. After resetting the error with the handheld testequipment. the problem occured again!!!
Is there any routine to reset the logic of the softtop N52?
Any suggestions to that problem??
Last edited by Matthias Sch.; 06-14-2020 at 06:49 AM.
If I disconnect the wiring of the softtopbow limit switch (S84/16) or leave at least the minus connection, the softtop bow opens as advertized (in my opinion a little bit too fast to the next position, I think normally it stops for a split of a second, but at least.....). The rooftrunk opens and the roof moves up to the 90° position and stays there. If the roof is closed again I can not open the trunk via keycontrol, neither the rollover bars move and when closing the bell doesn`t sound.
If I connect the plus-wiring again. I can open the trunk via keycontrol, the roll over bar works and the bell sounds when closing but the softtopbow comes out only a few inches as described before.
Last edited by Matthias Sch.; 06-14-2020 at 06:50 AM.
The power roof operation is based on the controller firmware cyclically evaluating the status of the position/limit switches as the roof opens or closes.
Shown below, are the pivotal stages of roof operation and the required status of the switches that must occur when opening the roof.
All those who have used this tool, have successfully diagnosed and repaired their power roof, for short money.
From what you have written, your roof fails to proceed opening at stage 4, which requires that all of the switch actualization's at stage 3 are correct and if so, then examining the status of the switches that should occur in stage 4 operation.
The best method to do this, is to operate your power roof to the point where it stops operation and then disconnect the wiring harness from the controller, at which time you'll be able to quickly check the status of the position/limit switch actualizations with a multi-meter set to read ohms (e.g. 1 = switched to ground and will show as 0 - 5 ohms and 0 = not switched to ground and will show as > 20K ohms).
Here is the diagram for the 55 pin connector on the controller.
Specific to what you have found so far.
Note that at the end of stage 3, the S84/16 rear bow locked is actuated, but then in stage 4 it is not actuated. When you removed the wiring pigtail at the switch, you physically unactuated the rear bow lock, which then allowed the rear bow to pivot up.
The advantage of checking the S84/16 status at the unconnected harness plug, is that it also checks that the wiring between the switch and controller is good. With the switch being mounted on the hinged soft top compartment cover, make sure that the wiring is not damaged (e.g. shorted to ground or broken), as well as the hydraulic lines (e.g. not kinked).
The S84/16 switch is actuated by a hydraulic cylinder and it's purpose is to tell the controller that the rear bow is locked or unlocked. The cylinder is differential, where the direction of motion depends on whether hydraulic pressure is applied to the piston or rod side. When the piston extends the soft top bow is released. Additionally, when pressurized on both sides the piston will also extend, because the force acting on the piston side is greater due to the active area. The cylinder differential movement depends on it's internal seals being in good condition.
It appears that your S84/16 hydraulic cylinder is kaput.
BTW, what you're currently experiencing with your key truck locking issue is to be expected, because the soft top controller communicates with the central locking system via the CANBus. As soon as the message "SOFT TOP UNLOCKED" is received, the
pneumatic system equipment (PSE), combi-functions (A37) no longer performs any remote trunk release operations. This is by design, because if the trunk lid were allowed to be open, it prevents the possibility of a collision between the trunk lid with the lid of the soft top compartment cover.
Last edited by Serndipity; 06-14-2020 at 11:41 AM.
thank you for the quick response and going so much into detail.
I knew your checklist already. Therefore I was convinced that the culprit must be the S84/16. But I was fixed on the electrical site because of the readout of the diagnosis which stated an error B1650-00.
The error 1010-000 is fixed after reloading the battery.
What came out today. I disassembled the mentioned hydraulic cylinder an checked the seals. Nothing uncommon. They looked good and I reassembled it.
After recycling the roof once manually ........ everything worked fine to my surprise. The roof went up and down twice without any problem.
At this stage (you can immagine) I was very happy and wanted to put all together. So I tried to open the roof again and .......... nothing, as described before. Same problem.
Now I checked the respective hydraulic cylinder on the main hydraulic unit and found a slightly worn out o-ring and replaced it. But this didn`t help out.
So I think, I have to buy a new cylinder for the S84/16 or do you think new seals will do?
1. Question: I found a small spring in the cylinder of the main hydraulic unit. What is this for??
2. Question: Is there another reset mode for the roof, besides opening and closing it manually???
Thank you again for your help.
Greetings from Germany. Stay safe and sound
Last edited by Matthias Sch.; 06-15-2020 at 02:04 PM.
-The internal seals, which typically are not O rings and are what provides the required 2 way movement of the piston.
-Opening and closing the roof is the only way to reset the position/limit switches.
-Not clear as to what the 'main hydraulic' is (the hydraulic pump assembly?). However, the S84/16 latch assembly does have a torsion spring, positioned at the far end, underside of the latch, adjacent to and on the same axis of a cam.
Diagnostic trouble code B1650-00 means that the 'roll bar retracted limit switch' (S83/5) has not actuated.
That may actually be the culprit.
Please check the actualization of your S83/5 switch, at the disconnected controller harness connector, when your roof operation fails at stage 2.
Note that to provide needed clearance for roof operation, the controller must see that roll bar is down, beginning at stage 2, though stage 10.
From other experiences, although the roll bar appeared to be lowered, the switch was not being triggered by the roll bar frame and was often repaired by adjustment.
I'll provide additional details, if you find that the controller is not recognizing that the roll bar has been lowered.
Last edited by Serndipity; 06-15-2020 at 07:31 PM.
I meant the o-ring (right red arrow on the picture) and the green seal. Is it better to buy a complete cylinder or ist it worthwhile substituting only the seals?
And sorry, yes I was talking about the hydraulic pump assembly. There is a spring in that mentioned cylinder (I think there is another one in one of the others).
Today I moved the rollbars out prior operating the roof. They move in as advertized and at the moment they are in the down position the soft top bow goes up (again only a few inches). So I think the S83/5 switch is triggered in the correct manner.
Error read out: In my opinion my testequipment reads out only a general error concerning B1650 by stating B1650-000 (I forgot one zero).
What happened today.
I removed the complete softtop bow lock and tested it hydraulically and electrically. It opened and closed without any problems. The values "ignition on" = 0 V (locked) and 12,4 V (unlocked) which are within tolerance.
I still believe it is an electrical problem.
- I measured the S84/5 with good results.
- I disconnected the pluswire of the S84/16 (because in this case the bow pops out completely).
- I disconnected the S84/15 behind the left side panel inside the car and then reassembled it
And ..... the roof was travelling as it should. After four cycles it continued the old way.
???????
Then I thought: let`s try it the other way round. I moved the roof manually in the open position. But in this case nothing happens when actuating the S84 switch in the cockpit to close it. One can`t even hear the pump working.
Last edited by Matthias Sch.; 06-17-2020 at 02:13 PM.
I removed the complete softtop bow lock and tested it hydraulically and electrically. It opened and closed without any problems. The values "ignition on" = 0 V (locked) and 12,4 V (unlocked) which are within tolerance.
I still believe it is an electrical problem.
In addition to measuring resistances to verify proper switch actulations (which is easy to do at the disconnected controller connector with ignition off) , comprehensive trouble shooting would also include measuring the switching voltages with the harness connected to the controller as well .
However, it requires a 126 pin breakout box with 55 pin test cable, inserted between the controller and wiring harness, which is very expensive (about $US3,000), but does help verify that circuitry inside the controller is not a problem.
By removing the ST bow lock and manually testing it (without the controller), indicates it is working properly.
In previous post, you mentioned that you were getting a 1010-000 DTC, which occurs when voltage at terminal 30 is to low, but went away after you charged the vehicle battery. The controller design specification requires an operating voltage for the soft top electronics of between 11 - 14 volts. If not correct, the possible cause could be a faulty controller or wiring issue.
- I measured the S84/5 with good results.
Good....the controller checks that S83/5 has properly actuated and the rollbar is down, whenever opening or closing the power roof.
- I disconnected the pluswire of the S84/16 (because in this case the bow pops out completely).
Previously you had mentioned that a your ST bow was raising only a couple of inches. When the latch opens, the force to release the rear bow flange is provided by a pair of tension cables. Normally the bow only needs to rise a couple of inches (sufficient to release the bow flange from the latch) and those cables are not under a lot tension and seldom are a problem.
What you're saying now is that the bow pops out completely, when you disconnect the S84/16 plus wire, as well as sometimes the roof operates for a couple of opening cycles then stops.
The S84/16 microswitch is a simple single pole circuit that connects controller pin 29 to ground when the ST bow is locked or not to ground, when the bow in unlocked.
However, a complete analysis of the microswitches, would always begin by making specific controller voltage measurements, which as mentioned above, requires the very expensive 126 pin break out box and test cable.
In regard to S84/16, when the rear soft top bow is locked, with the ignition on, the voltage at pin #29 and vehicle ground would be 0 -1 volts and when unlocked, measure 11 - 14 volts. If both values are not correct, an issue with the N52 controller would likely be the problem.
When you disconnected the S84/16 plus wire, that the controller analyzed the voltage values as being correct (e.g. pin 29 was no longer being shorted to ground), the bow completely released, allowing the roof to open.
The S84/16 is located on the ST compartment cover, which means that the hydraulic lines and wiring pass through the compartment hinge. Over time, there have been some problems with either the lines kinking or the wiring breaking or shorting out.
- I disconnected the S84/15 behind the left side panel inside the car and then reassembled it
The S84/15 bow up/down position/limit switch tells the controller if the bow is currently down or up (tells the controller whether bow lift cylinders should raise or lower the bow).
The switch is fastened (clamps) to the left side bow lift cylinder body and has a moving arm (attached to the end of the cylinder rod with a C clip), that extends or retracts as the bow is raised or lowered.
Here is the S84/15 electrical schematic diagram. The unconnected wire goes to ground, such that either bow down (pin 11) or bow up (pin 13) is actuated (connected to ground).
At stage 3, if the switch is properly set, the lift cylinders will operate and raise the bow to 90 degrees and stop when the sliding mechanism tells the controller that the operation has been completed.
And ..... the roof was travelling as it should. After four cycles it continued the old way.
???????
Then I thought: let`s try it the other way round. I moved the roof manually in the open position. But in this case nothing happens when actuating the S84 switch in the cockpit to close it. One can`t even hear the pump working.
Here is theelectrical schematic diagram showing how the controller is fused (powered), as well as the pump relay.
If the pump is not working:
-The power roof controller is not providing the signal (voltage) to the relay's coil, required to close the switching contacts.
-The relay's switching contacts are pitted, from the arc of switching large current and emf back voltage, caused by inductive loads.
-The 40 amp fuse in the trunks F4 fuse box is faulty.
-The pump motor has died.
Also pull the fuses in positions 11 and 13, in the trunks F4 fuse box and make sure that no corrosion has developed on the contacts, which would provide resistance to the required current flow.
Last edited by Serndipity; 07-26-2020 at 12:00 AM.
maybe I have to get back to the beginning:
The car was parked two days in the garage with the roof open. The day I want to drive out was a rainy one, so I had to close the roof in the garage. It didn`t move nore could I hear the hydraulic pump running.
After a few minutes of troubleshooting I saw that the rear windows and the mirrors didn`t move and I had a look at the fuses. I found that one broken in the trunk box F4. I checked the other fuses also
Then I changed the relais as well (I still have two new ones here).
Nothing happened. So I recycled the roof manually to the closed position.
From that point on the hydraulic pump sounded and the obove mentioned error appeared.
Before writing here I read a lot in the forum, specially your postings and those of TopHydraulic..
I took the error read out and measured the resistances through not finding any hint.
Thus I started with disconnecting the wires of the S84/16. As I was aware of a shortcut within those lines, I cut the wires and connected two new ones shortly before the wirings are going into the controller respectively to the switch.
I knew already about that breakoutbox. But ... where is the difference between measuring the voltage at the new wiring connections behind the controller or via that box. I could test the voltage at the connections and they appeared fine to me.
I also knew that the bow should go up immediately when released by the lock. So I had a look at the fabric tensioning belts and didn`t find any broken. Therefore I am really astonished that sometimes it works and sometimes not.
"I made a few trials and found out: when moving the ignition off and then to on again and then pulling the avtivationswith to open, the bow is moving further up in the 90° position. Then the cover is opening and the roof is then moving in an up position of about 90° and stopping there. It does not move any further. After recycling the ignition again I can only close the roof with the normal procedure."
Yesterday I tried the procedure from the open position. In this case, as I mentioned, nothing happens. But I can confirm that the pump is working when starting the procedure again from the closed position.
Don`t you think the N52 could be the problem?
Best regards,
Matthias
Addendum:
Yesterday I cut the lines of the S84/15 behind the left sidepanel and had some strange outputs on my testequipment, but couldn`t verify them in the evening. Today I remeasured. If I disconnect the lines, I can verify the correct voltage and resistance with the ignition to off. But if I reconnect them again, line 11 has strange readouts in the up position of the roof. The resistance is not > 20 kOhms but only at 1,4. I disconnected it and measured only the part of line 11 which is going from that position to the front of the car (I`m wondering why it doesn`t go directly back to the N52), the same value appears.
As I wrote before, the hydraulic pump is not working when in fully up position (cover closed). In this case I can hear only the relay switching. With a disconnected line 11 the hydraulic pump starts to work and wants to close the cover of the bow the whole time.
In my oppinion the error should be within line 11.. My question: where does line 11 go to the front direction (driver`s side) of the car? On the electrical schematic diagram I see it only running direct to the N52 which could not be in this case.
Maybe I will follow the way of that line today!
Last edited by Matthias Sch.; 06-18-2020 at 08:11 AM.
Line 11 is going to the front seat, from there to the passenger seat and back to N52. A long way!!!???
I cut the line near N52 and measured again.
Cut line direction to N 52
Roof completely down = 0 Ohms >>>>> good value
Roof completley up = 1.4 Ohms >>>>> bad value
Cut line direction to S84/15
Roof completely down = 0 kOhms >>>>> good value
Roof completely up = >20 kOhms >>>>> good value
So the error seems within the N52 or do I misinterprete that?
For me that is the reason why the roof stops at an angle of 90° going up when opening because this is the switching point between good and bad value. And in my opinion this is also the reason why the roof won`t go up from the fully open position because the value stays bad when the roof is in the compartment.
But is this as well the cause for the roof not unlocking correctly?
Last edited by Matthias Sch.; 06-19-2020 at 12:43 PM.
Without equivocation, because power roof operation is based on the controller firmware cyclically evaluating the status of the position/limit switches to hydraulically open the roof, all that would be necessary diagnose a faultycondition, would only be to use the diagrams showing the pivotal stages of roof operation and the required status of the switches that must occur for the roof to continue operation, which can be simply done by operating your power roof to the point where it stops and then with with the ignition off, removing the 55 pin harness connector from the controller, at which time you'll be able to quickly check the status of the position/limit switch actualization's with a multi-meter set to read ohms. A position/limit switch is actuated, shown as a 1 (e.g. switched to ground and measured as 0 - 5 ohms) or not actuated shown as a 0 (e.g. not switched to ground and measured as > 20K ohms).
As the controller analyzes the positions of the limit and operating switches, that correspondingly operate the solenoid valves (Y56/2y1.....Y56/y7 and Y57/1) that actuate the hydraulic cylinders, this method alone is non-destructive, will quickly provide key insight into malfunctions that cause the power roof to fail from fully opening and It is ill advised and not necessary to be cutting wires, measuring voltages, dissembling cylinders etc..
Based on the information you provided in your 1st two posts (#'s 12 and 13), based on your observed symptoms, where your rear bow was failing to pivot up 90 degrees hydraulically during stage 4, in post #14, I suggested that the cylinder that actuates your S84/16 rear bow unlocking function, was kaput and suggested that you verify by examining the required switch actualization's that take place during stage 4.
As aforementioned, the internal seals, inside the cylinder, are what provides the ability for the rod to extend, retract as well as the required range of movement, for the rod to extend to unlock and unlatch the rear bow.
Specifically, the first thing that should occur in stage 4, is that the S84/16 must change from it's stage 3 locked actualization to a unlocked actualization (because logically before the bow can pivot up, it needs to be unlocked). The next thing that should have occurred in stage 4, would have been for the bow lift cylinders to pivot the bow up. However when the controller saw that rear bow was still locked, it was illogical to raise the bow.
The reason behind the intermittent roof operation you experienced:
By design, by pressing or releasing the S84 operating switch, the soft top operation can be interrupted (stopped) and later be resumed from that point (either backward or forward) and the soft top controller DTC's clear, whenever the ignition is turned 'OFF' and 'ON' or
a change in switch state occurs.
As example:
When you removed the positive wire from S84/16, you were able to hydraulically close the roof, because the switch was no longer connected to the controller and switched to ground and locked. If not switched to ground, the controller would now see the rear bow as unlocked and proceed operating. However, when the roof was closed, the controller would still see the rear bow as being unlocked, which would be implausible. Actually, doing that was a good troubleshooting step, that would manually simulate that the rear bow unlocked (fool the controller), but it would have been less destructive by just unplugging the switches pigtail connector.
my logic is/was different.
As the error started with a blown fuse and in the open position of the roof, I was evaluating the problem from another point of view.
From the closed position I had the problem as described. So for me there must have been at least two errors not operating the roof correctly. Even my be three errors because after operating the bow, the roof went only up for a 90° position.
What I did in the meanwhile:
Disconnected the 84/16 microswitch and laid two electrical cables to the front seat:
1. tested the old microswitch which is actually a Marquardt series 1022 (this is much cheaper than buying a complete latch; I could get a used one for round about 150 dollars, a new one from Mercedes for 900 dollars!!!!) from the drivers side >>>>>> same problem: latch opens and the bow opens only a few inches
2. simualting the switch only with the plus/minus wires connecting and unconnecting >>>>> same result as above
3. tested another similar microswitch which I had handy >>>>>>>> same result
4. buying a 1022 microswitch for 10 dollar (it is not exact the same switch; the positioning plate is missing. But if you know how to handle that, one can use it.) >>>>> same problem.
So my logic said (already from the beginning) the switch can`t be the culprit.
I bought a used N52 control module for ~ 195 Dollar.
It arrived yesterday.
Two minutes of work and the roof worked as it should, without making any manual reset!!!!!
Your soft top controller is ending further operation, after the rear bow unlock operation, because it has sensed a fault. Additionally, you're able to re-lock the bow again, by turning the car off and on, because the controller reboots.
After the rear bow is unlocked hydraulically the bow should pivot up hydraulically, until in a position of approximately 90 degrees.
If the controller does not think that the rear bow did not unlock properly, further roof opening will cease. Possible anomalies could be:
I'll try to explain why, but hydraulics are above my pay grade (Klaus please feel free to chime in here). To permit operation in both directions (lock and unlock) this is a double acting differential cylinder, having pressure connections on both the rod and piston side. The sequencing of the necessary system pressures are determined / controlled by the soft top controller, via activation of solenoids in a value block (Y56), which is part of the hydraulic pump. The culprits causing the problem could be leaking internal cylinder seals or the soft top bow lock open valve (Y56/2y6).
If the soft top bow does not raise or only raises slowly, the possible culprits could be:
- Soft top bow locked limit switch (S84/16)
- Soft top bow raise valve (Y55y8)
- Faulty left or right bow cylinders (these are also differential cylinders).
I've enclosed a number of thumbnails to help with understanding the complexity of the power roof system, locate the referenced components etc..
In addition to the likely primary culprits mentioned above, there can be secondary system anomalies preventing the rear bow from unlocking or raising as well. Examples would be:
- No vehicle speed signal input to the controller
- Voltage supply to the controller (low voltage or 1 of the 3 fuses faulty)
- Soft top locked left limit switch (S84/11)
- Roll bar retracted switch (S83/5)
- Other value block malfunctions confusing the controller
- Wiring harness faults (shorts, broken wires, faulty ground returns)
- Controller lost synchronization from attempts to operate roof on low voltage
Diagnosis and repair by a qualified repair facility will most likely be $$$$$$.
However, if you have strong trouble shooting and DIY skills, the cost to repair can be 0 to $$. You'll find a lot of help from the veterans here and Top Hydraulics can rebuild all the hydraulic components. There are numerous existing threads that will bare this out.
Should you want to tackle it yourself, you might start with some basics.
- Level of pump fluid is correct.
- All 3 fuses OK
- If the pressure relief screw was turned to reduce pressure, it's turned back to maximum
Note: Your current issue coincides with the first power roof hydraulic operation
- Re-Synchronize all the limit/position limits by fully opening and closing the roof manually
Thereafter, getting the trouble code print out from the MB STAR Diagnostic System might be a good investment. If you do this, have the tech clear any of the stored fault codes (sometimes this alone restores roof operation).
So my bow lock solenoid was leaking and would only let it lift slightly and switch would flash. Once I repaired the leak it was fine. Seems like the pump notices the pressure drop and shuts off
03-10-2016, 06:07 AM
