Z4 roof only closing half way - (NOT THE PUMP!)

[Anonymous]

HI, I know this topic appears to be talked about to death but I can't find my symptoms out there, so if anyone can help....

1/ Roof is in fully open position and locked. I press the button and it raises about 2/3rds the way then stops (i.e. 1/3rd open). Red light on dash flashes. Pressing any button does nothing and all appears locked. (OK who's the first to shout 'water in the pump!' )

2/ Use manual release for hydraulics and let it fall to the closed position. Reset manual release and try to finish closing the roof, no movement. So I allen key it closed and the red light on the dash still flashes at me .

3/ Well I thought OK, maybe it's the pump, so I manual released the roof, and opened it up so it rested in the open position. I then tried the button to finish opening it and it worked locking it fully open. So thought maybe I could close the roof and I pressed the button and again the motor worked but then got stuck about 2/3rds closed again .

4/ So this time I thought I'd play a little. With the roof somewhere between 1/3rd and fully open the motor works and it will lock the roof into the open position fine. I could open/close/open close until the cows come home so long as I don't close it more than half way. But, as soon as it moves towards the closed position it stops and the roof is left slightly open and no buttons work.

All this sings to me that it is a sensor, or a computer issue (also consider wiring but as it is really consistent in where it decides to suddenly stop I can probably rule this out) ....... I was really hoping one of you smart guys out there could shed some light on the fault and specifically where to look.

(Oh, and just to make certain, these tests were carried out with the car running (so no battery issues) and the parcel shelf in the down position (no amber light showing on the dash!)

Fill your boots and lets see who can come up with the first sensible solution that isn't the pump sitting in water ?

 

[benlumley]

I have no idea......

Thinking logically though, I wonder if something is broken with the parcel shelf switch and it is somehow getting knocked/pushed/whatevered as the roof folds into place in the boot - hence it cutting out half way.

Given that I have no idea - I'd let someone more knowledgeable ridicule my suggestion before you go looking for this as a problem!

 

[fixit man]

HI, I know this topic appears to be talked about to death but I can't find my symptoms out there, so if anyone can help....

1/ Roof is in fully open position and locked. I press the button and it raises about 2/3rds the way then stops (i.e. 1/3rd open). Red light on dash flashes. Pressing any button does nothing and all appears locked. (OK who's the first to shout 'water in the pump!' )

2/ Use manual release for hydraulics and let it fall to the closed position. Reset manual release and try to finish closing the roof, no movement. So I allen key it closed and the red light on the dash still flashes at me .

3/ Well I thought OK, maybe it's the pump, so I manual released the roof, and opened it up so it rested in the open position. I then tried the button to finish opening it and it worked locking it fully open. So thought maybe I could close the roof and I pressed the button and again the motor worked but then got stuck about 2/3rds closed again .

4/ So this time I thought I'd play a little. With the roof somewhere between 1/3rd and fully open the motor works and it will lock the roof into the open position fine. I could open/close/open close until the cows come home so long as I don't close it more than half way. But, as soon as it moves towards the closed position it stops and the roof is left slightly open and no buttons work.

All this sings to me that it is a sensor, or a computer issue (also consider wiring but as it is really consistent in where it decides to suddenly stop I can probably rule this out) ....... I was really hoping one of you smart guys out there could shed some light on the fault and specifically where to look.

(Oh, and just to make certain, these tests were carried out with the car running (so no battery issues) and the parcel shelf in the down position (no amber light showing on the dash!)

Fill your boots and lets see who can come up with the first sensible solution that isn't the pump sitting in water ?

Welcome to the forum.

It might be timing out, happens to mine sometimes if it takes to long to close red light flashes (i think) and it stops, I turn IGN off & on again and continue closing Have you tried that ?

Mine needs more hydraulic fluid I think but when I'll ever get round to doing that I don't know, pita to take the roof off again just for that !

 

[Anonymous]

Benlumley, thanks for the thought, I've checked and there is definitely not anything catching or wiggling the shelf around the time it stops, maybe I try shorting out the switch when I have time, just in case though.

Fixitman, hadn't thought it could be timing out, but I doubt it's that, since turning the ignition on and off still leaves it in the hung state with no response from the buttons. Also, for the part of the opening cycle that the roof will move it moves pretty fast and this is when it does most work, so I reckon the pump is still in good condition. The other strange thing is even when I manually close it I still get the flashing red lights after I allen key it.

Could it be a sensor has moved or that one is misreading?
Also, if its a computer thing, does anyone know if there is a way to reset/reinitialize the computer? What will I lose on the car if I disconnect the battery over night?

Another thought, as you mentioned it, what would the symptom be of low hydraulic fluid, is it slow movement of the roof or would it only move part way....? Also, I can probably guess the answer but I'll ask anyway, is there any easy way to check/refill the reservoir?

Thanks in advance for everyone thoughts and advice.

 

[fixit man]

Hi,

I'm not aware of any sensor that could affect the closing at mid range.

The fact that yours does not reset after ignition on/off reset means it's hasn't timed out...so I doubt it's low on Hyd. fluid, symptoms that I know of are.. it takes a while to get going , goes fast then slow etc. as there is probably air moving around the sysyem.

To top it up you have to take the roof off, but i'm sure this is not your problem, and I have no more Ideas about this problem ...sorry , OK maybe one....

Have you tried assisting the roof by hand when closing to see If it helps, could be internal leakage in the hydraulic rams ??

 

[Anonymous]

Yep, tried but it gets to a given point and locks rigid in the air then very very slowly move down by the weight of the roof. If I release the hydraulics it all moves freely.
In some way I'm glad I'm not going mad and it is something new, but I also want to fix it.....
There must be someone out there with new ideas

 

[Anonymous]

I'm wondering. Last week I was cleaning the car and I had the roof part open to get into all the crevasses. It was left like that for quite some time. Is there a chance it has triggered a safety mode in the roof computer stopping it from going past this point?
A long shot I know as the roof did close automatically after the clean. But I don't think I'd had the roof down since.
I would still like to reinitialize the computer if possible. Anyone know how, is there something with an initial config when installing a new roof system?

 

[Georgio]

I know this might sound obvious but have you tried WD40ing the roof joints?
Mine was a bit creaky when I first got the car, so lubricated all the joints with the roof open halfway and it smoothed it right out.

 

[Anonymous]

So I tried something else... I opened the roof half manually and finished it off with the electo-hydro system which locked it in place and the light went out. All happy and normal. I then switched off the car, released the roof and moved it manually and then used the Allen key to lock it to the windshield. I wanted to know if the computer would recognise it was in the fully closed position and not show a red flashing light, unfortunately I failed :-( I turned the key and on came the flashing light.

This must indicate something electrical mustn't it. My thoughts are, could it be a sensor and are there any electrical wires in the roof that could also be causing a problem?

Thanks georgio, I'll give it a go later it, definitely won't do any harm, but after the little test above I don't hold out lots of hope.

 

[fixit man]

Hi,

have you got a fault code reader ?, this could tell you something ? I did a search and apparantly (maybe you knew this) the roof does have an ECU.
Last time I was using INPA program on my car I remember it going through tests which included the roof system !

 

[bcworkz]

I've no idea either, but it's conceivable the greatest hydraulic pressure is required mid-travel, either end of the travel may require less pressure for operation. Someone with better knowledge of the hinge and ram geometry may be better equipped to say one way or the other.

If that's the case, it still could be the roof motor, or the frame is binding for some reason, air in the system, etc. Does not really help diagnose the problem as much as just explain the behaviour. Food for thought anyway?

 

[Anonymous]

Thanks bcworkz, I understand your logic, but still think it is unlikely to be the pump. Sometimes the roof makes it to nearly the windscreen and then stops, so I don't think that it is working the hardest when it stops. When it stops, it stops suddenly and doesn't slow down first. Also, all I have to do is manually release the roof, move it back open a bit and release the hyd lever and bob's your uncle, the motor works to open and close the roof (but not close it completely still!)

Also I don't think this answers the fact that when the roof is completely closed it still shows the red light and nothing will work, not even the motor in the unlock roof mechanism. I really think there is something that is electrically inhibiting this mechanism. However when the roof is completely opened and locked, there is no red light and when pushing the button the roof unlocks and the roof will move the first half or so back and forth constantly with no issues. The roof will just not completely close.

I'm really really perplexed :?

I've tried looking at the control box and connectors, it was reasonably accessible behind the left seat and seemed to be clean dry and with no frayed cables. I'm struggling to get access to the hall sensor though, that indicates the roof is fully opened or closed. Can anyone help with some photos of this region with where to look. Can I get access to it without removing the roof?

Unfortunately I don't have a fault code reader so can't interrogate the ECU/roof computer. I would love to reset it somehow, so I've pulled the CB's that I think are related to the roof computer and I'm leaving it overnight. Not sure if it will work though. I don't need the car for a few days, so would I do any harm if I disconnected the battery for a few days?

 

[Anonymous]

Well, partial success. I got to a fault code reader and it is telling me that when the roof stops and goes no further both the open and closed sensors are triggering. I guess these means the computer can't trust anything and so stops and registers a fault.
Now I really need to get to these damn sensors. Maybe there is a cable fault or a misalignment issue. Is there anyone out there that photos of the sensors and advice on how to get to them

 

[fixit man]

found this :- http://forums.bimmerforums.com/forum/showthread.php?1122711-why-does-the-red-light-keep-blinking-when-I-fully-put-the-top-down

more specifically this :-There are five switches not including the center console switch.

Switch Located in the Trunk
1. Convertible Top Compartment Floor Switch.


These next switches are Hall Effect switches.

Switches Located on the Top Hard Mounts. (must remove top from car to access)
2. Convertible Top Lowered Switch
3. Convertible Top Closed Switch

Switches Located in Locking Mechanism at the front of the top.
4. Scuttle Release Switch (Convertible Top Locking)
5. Scuttle Lock Switch (Convertible Top Locking)

from our friend shipkiller(legend)

 

[Anonymous]

Sorted!!!! (for now anyway......)

Thanks everyone for the help

After trying to get the cover off from the front of the roof where the motor is and failing miserably, I decided to make sure the roof still moved in the half open position and it did. Roof still wouldn't close though. So I tried a last ditch attempt, I pressed the close button and at the same time put my hand in the roof and wiggled the cable in the roof that sends the sensor information for the locks......Guess what, after a few wiggles the roof started to move, it opened and closed with no problems what so ever.

I feel vindicated in believing the pump was fine and it was a some sort of sensor/cable issue

My quest is not finished yet though, I still want to get the cover off from the locking motor and work out why there is the intermittent connection. I want to check that there cable is undamaged and connector is secure around this region. Can anyone tell me how to get the cover off without breaking it. All I found were 5 screws, but it was still to stiff for me to move. Can anyone explain 'the knack' needed to remove it?

Nevertheless, I can again enjoy the beauty of an electric roof uncovering the clear blue heavens above. Nothing quite like natural air con. Praise be the Z4

 

[fixit man]

well done, can't help with getting the cover off..not even sure which switch you're talking about,Is it at the front over the windscreen ?

pls. If you get a chance take a photo, I'd be very interested to know that switch location.


About feeling vindicated ..I don't think anyone doubted your feeling that it wasn't the motor..I didn't anyway !

 

[Anonymous]

Yep, it appeared to be the cables leading to the two sensors above the windscreen. If I get the cover off I'll post some photos, but I'm not going to force it, and whilst it works I'm not going to fiddle too much.
I guess the vindication was against the BMW garage that read the fault codes. To their credit they read the codes for free, but then tried to say it was more than likely the hydraulic pump and would cost around £1300 to fix! Once again my faith in garages is seriously knocked!
Thanks again for all the support, everything helps

 

[fixit man]

yeah F%&ing Stealers , they'll say anything to get some money out of us

 

[Anonymous]

Found it, courtesy of srhutch and a little searching. I found this online version of TIS that works fine with google translate
http://tis.bmwcats.com/doc1080897/
I found the extra 2 screws hiding at the sides of the roof only after I lowered it about 2/3rds and hey presto I could take the trim off. I checked the sensors and they seemed fine, however it appears the cable is giving me jip. So nearly there, think I need to splice in a new section but no time now, will finish the job next week.
Thanks for your advice and happy cruising

 

[Anonymous]

I'm not sure if anyone is still monitoring this thread, but wanted to let you know that I finally got a bit more time and cut open the wiring loom in the roof around where it heads under the plastic. I found all three sensor wires were kinked, one of which was broken completely. Looks like bad manufacture of the loom. I've cut out bad bits and soldered in a new section. So pleased I worked out the problem and managed to fix it. Would never have been possible without all your help. Thanks guys. (If anyone knows how to put a few pictures on this thread let me know how and I'll gladly do so.)