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Discussion Starter #1
I was most interested to read VOXMAGNA’s posts on the subject. Just recently the boot lid latching motor in my EOS 2006 stopped working. Whilst the boot lid can be closed manually the latching motor does not run and when the roof has either been opened or closed, I get a warning on the dash that the boot lid is open. When the boot lid is then opened and closed again manually the warning message disappears.
After removing the internal boot panel, I notice that the roller pillar on which the boot lid claw operates remains in a down position as if the latching motor had operated.
After removal and dismantling the latching motor unit, when power is applied to the motor terminals, the motor itself runs in both directions. Reinstalling the motor unit after manually resetting the position of its internal gears and the associated drive bar and so raising the roller pillar, when the boot lid is closed, the latching motor operates correctly once. On reopening the boot the roller pillar remains down.
Without a wiring diagram, it is difficult to understand the process of the powered latching mechanism. The two cables supplying permanent live and earth test ok and the fact that the latch motor worked once after being reset suggests that this side of the supply mechanism operates correctly. I have however been unable to check the continuity of the wiring that I presume should operate the lifting of the roller pillar when the boot lid is opened. The internal pull in the driver’s door, the mechanical release using the VW boot emblem and the remote “key release” all work satisfactorily but the roller pillar remains obstinately down!
I would very much welcome suggestions on how I might resolve this problem
 

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The roller pillar as you call it is the motorised lock keep. When the lid is closed the motor whirrs and the roller moves down for the pull down, which tensions the lid on its seal.

The lock unit electrically is fairly simple but the path to a solution may not be.

First as you appear to have done, you check the motor and latch mechanicals to ensure the parts move freely. There's a trunk release button with 2 wires associated with the V.W emblem release (purple & brown). They probably come from the upper latch assembly in the lid? You can check those. Because the lid moves, the few wires from the lid are taken down one side and clipped to the roof hinge. These are always being flexed and broken wires are a potential fault possibility.

The motor/lock unit only has 3 wires Red/Blue and Brown should be the motor and Brown/Black should be the switch wire. The motor is bi-directional to lift and lower the roller. The third switch wire can tell the system if the roller bar is raised or lowered but it can also be used to power the motor when the switch is closed. You should be able to test the motor by putting power on the motor wires for one way, then reverse polarity for the other whilst looking for an output voltage on the switch wire. I don't know if the switch is open or closed for the roller up/down, but it doesn't matter as long as the voltage changes for the two extremes. You should be able to see the switch contacts in the assembly? Another way to check the switch in the motorised assembly is to connect a small 12V bulb between the Brown/Black switch wire and the Red/Blue motor wire. Apply 12 volts to the Red/Blue and Brown motor wires and the lamp should light for the roller in the top or bottom position. Reverse the test voltage to the motor and the lamp should do the opposite - (come on or go off). Note: V.W wire colors are not always consistent!

That was the simple stuff. The lock motor and its switches are connected to the convenience system control unit. This electronic controller gets commands from various trunk switches then drives the motor and its roller up or down. The controller uses the lock motor 'position switch' to inform the roof controller et Al when the trunk lid is open or locked closed.

If you have checked the motor and switches are o.k disconnected from car, the next step is to check if voltages are getting to the motor (and leaving it on the switch). I already explained how you can simulate the lid open and closed with a screwdriver operating the latch in the lid which should allow you to connect a voltmeter to the lock motor and simulate lid open and closed. If there is no voltage getting to the motor, you have to check wiring between the motor and the Convenience Central Control Unit. If you get a voltage but it is only one way not reversing (roller bar down only) then that looks like a faulty control unit. :eek:
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Discussion Starter #3
Thank you so much for your helpful information. I will work through your guide and check the operations in detail hopefully this will identify the fault.

Since my last post, I have spent some further time examining the motor unit and components on the circuit board. The switches that operate on the drive bar both work satisfactorily and there is no evidence of failure that I can see on any of the components except when I ran tests on the two relay units by applying voltage to the coils and checking the switching; difficult with only one pair of hands! One of the relays, the one nearest to the incoming cable connector, was much quieter than the other when power was applied. The same one, without being energized, showed a resistance rather than a closed circuit as it should in the normal on state.

I hope your guide will throw out the answer but in the meantime, I have ordered a replacement relay from RS Components which I will substitute if not. Your thoughts would be most welcome?
 

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Post up some photos of the lock unit as they help others to understand. The lower active part of the lock unit is open and water can get inside. Automotive relays are usually not sealed and I've opened up many in the past. They can get welded contacts which would make it sound weak compared to a good relay. I assume you confirmed the coil resistances of both relays were the same?
 

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I have just had some bad experiences and I will re-visit this post. Basically to do some serious roof fault finding I disconnected the roof controller and I mean ALL the connectors A-D. And so it was with the trunk lid swung out and the roof in the service position I was happily testing out all the roof sensors and wiring. Until it started to rain and I had to get the covers over. I easily closed the trunk lid from the swing out position and lowered the rear window frame, but then next morning found I was 'locked out' and it took me 2 days to get in without damage. I need to do a post explaining what I did.

The lock has 2 functions. First there's the lock motor in the top half of the lock that rolls the 'C' claw around the roller which is the 'clunk' or 'click' you hear. Second is the 'pull down' which uses a second motor in the lower half inside the trunk to pull the roller down and hold the trunk lid closed with (a lot of ) tension on its seal and holding the lid gas struts. Normally with full electrics working, the upper lock activates the lower pull down when locking and raises the pull down and unlocks the 'C' claw when unlocking. Both occur together, although it is the upper lock mechanism in the lid sending the up down signal to the lower pull down motor. These functions are all done through the roof controller and with mine disconnected, there was no function. The pull down motor is controlled by logic level signals so it has control electronics inside, whereas the upper locking motor is simpler and follows what V.W have always done on other brands. Unfortunately, unlike other brands where you climb into the trunk behind seats, the EOS has a structural partition and you struggle to sort out problems through the ski hole - unless you are a midget.

So I go to the emergency lock release at the bottom of the ski panel and pull - NOTHING happens. I had already suffered torture releasing the trunk lid corner claws (trunk lid in swing out mode from stopped roof op.) So what the heck!! I have the rear panel already removed and I can see the lower lock lever pushing up, but the trunk lock is still held and I can feel the roller hitting the top and bottom of the upper lock 'C' claw but the claw isn't opening. O.K so it must be a friction problem stopping the upper lock 'C' claw from rotating? I tie a bungy to the release ring and go around to the trunk lid where with very little effort I can move it a small distance up and down, so the claw isn't held by friction against the roller?

Eventually, I found a totally off the wall way of activating the pull down and discovered the emergency release only works when the lid is pulled down tight against the seal. If the pull down roller is raised to where it would be when you open the trunk, the emergency release does nothing. Now that sounds fine for a normally working car, but in the middle of a roof Op. if things go wrong, the pull down is raised for the lid swing out!! That is how the emergency unlock seems to work on MY07 and I haven't been inside the upper lock yet to try and understand why the 'get out of jail' designed by V.W doesn't work (for me). With my trunk lid now open I have painted the pull down horizontal slide bar - Red shows when the lid is pulled down and Green when it is raised - although you can just about see daylight at the bottom when raised. I have also added a couple of wire taps and run wires that can stay close to the ski hatch to operate the pulldown/pull up so I can pull the emergency release and actually get the lock open.

With considerable time and patience I am creating my own methods to fault find my roof sensor and wiring issue with the roof controller totally removed. It's laughable to read the shop manual frequently refering to putting the EOS roof in this and that position, when in the real world you may not have any electronic control at all and that includes the trunk lock! The first thing to be done on a faulty EOS roof is open the pump control valve and before that you have to get into the trunk!

Have fun!!
 

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Discussion Starter #6
It is a little time since my original post on the subject of the Boot Latching Motor on my 2006 EOS. The guidance from Voxmagna was very helpful.

It took some time to discover the cause of my problem however and fortunately it did not involve the complexities of the roof controller. After further investigation and dismantlement of the latching motor unit, I found that there was excessive end float on the electric motor shaft. Whilst the motor would run satisfactorily in both directions when removed from the enclosure and voltage was applied, when reassembled I found that the motor shaft and gear was binding on the end bush and causing the motor to stall. The only option seemed to be to replace the complete unit but a little experimentation has so far saved the day; by inserting a couple of very small washers on the motor shaft between the gear and the locating end bush and a little LM grease, I found that the motor would run in both directions. After reassembly and reinstalling the unit, I am pleased to report that the latching motor is now working fine. Of course it remains to be seen just how long this temporary fix will last?
 

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It's probably too late now but I was wondering if you could add anything to my comment on the emergency release, whether it's just my lock or all of them? The emergency release pushes up a lever into the upper lock unit where the black square is to release the 'C' claw which wraps around the pull down roller. It only has a small spring tension when closed. In my case, if the tension roller is raised AND the upper lock is closed over it, the emergency release does nothing! This is the scenario for the trunk lid swing out and they may in their ignorance have stopped the emergency release working. But it's the frustrating scenario of being unable to open the trunk if the roof cycle doesn't finish correctly to access the pump release valve.
 

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Discussion Starter #8
Hi voxmagna. I am sorry to be so slow in responding. I am afraid I have had no need to operate the manual release for the boot lid and am unable to comment on its operation in detail. If you would like me to do some further investigation on my EOS please let me know!
Going back some time, soon after I first acquired the car, I had problems with the roof mechanism which stalled when I was trying to raise the roof. This happened just after the roof top had re-engaged in the screen leaving the rear screen and boot lid open like a giant air scoop. In the end, I had no option but to close the boot lid and window manually and take the car to the local VW dealer who replaced the "faulty" roof control unit. They had to use the manual emergency release to get into the boot to carry out the work. The "fault" with the roof control unit had apparently been caused by corrosion due to water ingress into the boot! I am still not entirely sure that the control unit was the real problem and not just corrosion to the wiring terminals which they also replaced at some "cost", but that as they say this is now just "water under the bridge"
 

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Thanks. I'm more advanced with some of these issues now. Water in the roof controller is at first hard to understand and many find it. I think I have a fix for that potential issue, but when V.W stick a huge rectangular hole in the body panel sitting over the roof controller it's like having a house with no roof! I have already posted about their love affair with water absorbing foam, well they put a layer of it inside the compartment housing the roof controller and the same on the right side for sound deadening. I've dried mine out and sprayed clear coat lacquer sealer all over mine. When I had the roof controller out, I stripped it down to the circuit board. It is actually quite well sealed EXCEPT where the connectors come out. I have the giant scoops at the moment and my car cover still just about covers all the open roof parts. I've got used to looking at it now.
 

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Discussion Starter #10
That is real bad luck. As you say the roof control unit is very vulnerable both from above and the side from the slotted ventilation panel, the later positioned to exit externally behind the inner wheel arch panel. I found that the slotted flexible slats in mine don't seal properly and the panel will have to be replaced. In the meantime Duck tape is my temporary solution. I am not sure why this ventilation panel is needed unless it is to avoid a build up of air pressure when the boot lid is closed? Despite this and the removal of the sound deadening material, the area remains damp.

I retained the "faulty" control unit and cleaned up all the individual terminals with Deoxit and was contemplating reinstalling it to check to see it is faulty or not? The board itself is well protected in lacquer and shows no sign of component failure though as a result, the testing of individual components would be difficult. I decided not to try reinstalling it however as I believe the roof system may need to be re-programmed when the controller is changed.

One of the most vulnerable parts of the roof system is the hydraulic pump and motor which drives the system. It is positioned out of sight in the boot cocooned in a foam enclosure which sucks up any stray moisture, leading to failure of the electric motor that drives it and corrosion to the pipework and pump. I was quoted over £1000 by the local VW dealership for replacing mine. VW apparently only sell the complete pump and motor unit. Thank goodness for www.roofmotors.co.uk who are able to offer exchange units either complete or just the electric motors at much reduced cost. Drying out the foam enclosure and carefully wrapping it with the pump unit in heavy gauge polythene seems to have resolved the problem for the future.
 

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I found that the slotted flexible slats in mine don't seal properly and the panel will have to be replaced. In the meantime Duck tape is my temporary solution. I am not sure why this ventilation panel is needed unless it is to avoid a build up of air pressure when the boot lid is closed?
It's too soon to do one of my long posts on 'Ventilation' but now my EOS has a lot stripped out I'm dealing with some things: The rubber flaps you saw are there to close up the car except when a door is open or when it's moving, I'm pretty confident that isn't where water comes from. I'm going the other way to enhance fresh air ventilation to stop some of the internal condensation I get when my car is parked up a week or so. I've actually pushed my fingers into each square flapper and pushed it up leaving a clear air path. I tried to remove the assembly but couldn't get it out (just a warning!) They appear to be clicked in from the rear of the aperture, My inner wheel arch in that cavity was absolutely dry. I sprayed some matt black over their heatsink - every little bit of cooling helps! I've cut a 'panel' of black nylon fly mesh and stuck it over the hole, if any water gets near that from the wheel arch (which I doubt) it will stop it pouring straight in.

As I said, their sound deadening foam lining in that cavity is another V.W open cell foam disaster. When you get internal condensation inside a car, not only are you looking for water leaks, but foam like that can stay saturated with water, hidden out of sight. I've been doing humidity measurements and it puzzled me after an overnight dehumidify to 40% over 2 consequtive dry days, humidity started to rise again and that's one reason.

So how is water getting to the roof controller? They put another huge hole just above it then stick some more of their nasty water absorbing foam on the underside of the side trim lining. It's my opinion that water gets into the fish tanks further forwards and if your car is parked on a slope or you brake, water runs down the sides over the wheel arch curves, under the trim and through the foam over the top of the roof controller.

What am I doing? I've got some 'Mini' rubber bonnet edge seal I've now fitted around the edges of both top apertures and I shall be removing their foam from under the trunk side trim. This seal has a raised soft flexible tubular profile like a door seal and will act as a stop for any water trying to get in. I'm assuming some water may get into the fish tanks which I'll look further into, but assuming it could roll down over the wheel arch curve into the trunk, I shall silicone a vertical strip of pvc just forward of the roof controller aperture to act as a dam and make it run down the side. The ultimate aim of course is no water, but I don't want to make it so easy to wet the roof controller. I shall repeat on the other side.

I've bought some gray 80mm circular soffit vents. One will go in the abs cover over the aperture and one will go in the cover into the side aperture. I've removed the stuffing bags to get air into the cabin through the hinge apertures and might consider fitting black soffit vents into each side trim cover near the seat belt, to achieve positive air circulation through the car. Once I pushed open the flappers, I could feel air movent on the back of my hands.

You're a bit late to the table on the EOS roof pump, been there and most of us have done something about it:


The pump needs free air circulation otherwise (in Summer) it may trip on over temperature. Fortunately, you just leave everything for 10 minutes until the dash dings stop and you should get back control. Not so good if it starts to rain whilst you are waiting though.

Lacquer on their controller pcb is no problem. A sharp probe will go through it and it usually melts off with a soldering iron. Working out where the current drivers are is an interesting challenge.
 

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Many thanks for the update. As you say it is entirely possible that water might make its way from the "fish tanks" on each side of the car. As the plug at the bottom of each "tank" appears to be solid, I am not sure how any water that might accumulate can otherwise find its way out. As you suggest further investigation of the means of diverting water away from the area roof control unit will be helpful.
The angle of the vehicle when parked is I think very relevant. I have a sloping drive which could mean that water runs off and finds its way into the bottom of the boot and even a small accumulation of water can find its way towards the rear of the boot and cause problems with the roof motor. Posibly because of the past problems with the latching motor, I can see clear signs on the underside of the boot lid that the seals are not doing their job properly. Now that the latching motor is working satisfactorily, some further adjustment of the alignment of the boot lid may also be necessary.

It is appreciated that overheating of the roof motor needs to be avoided but its rubber enclosure surrounds the motor unit almost completely and the potential for ventilation is very limited. The addition of a polythene wrapping simply stops any water absorption up from the boot floor. When I fitted the replacement electric roof motor, I found that the condition of the roof pump box does have an effect on water retention. I replaced the box when replacing the motor unit as I found the old box was acting just like a sponge. Squeezing it produced a flood of unwanted water, definitely the source of corrosion and damage.

I would be most interested to learn when you complete the reinstallation of your roof control unit whether it is necessary to reprogramme the system? I think substituting the old control unit for the new one is the most obvious way to test whether the old unit was faulty!
 

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In my post I measured how much water the OE foam box can hold. If you search there's another post from me about making a drain in the trunk floor, although I said this was last resort and leaks should be found and stopped first. When you do my mod. as I wrote it, the pump is effectively 'suspended' allowing more space around it for cooling and I don't get over temperature lockouts.

I also posted how to reduce water retained in the trunk lid lamp assemblies emptying into the trunk when raining, when you opened the lid. I think my first post here years ago was about the direction of parking. I left my EOS on front wheel ramps in the rain for a couple of days and got loads of water out. A lot is down to their stupid rear channel below the rear window which overflows and water then pours into the trunk if the flimsy wiper seal isn't good (which it won't be). Parking downhill is always better than uphill. I'm surprised V.W didn't put a 'ding' alarm for that in the mfd.

I don't expect to do any reprogramming. Maybe clear some fault codes with vcds. There should be no adaptation to do.

My pull down motor puts a lot of pressure on the bottom trunk seal. If your seals aren't being compressed, I think you have to adjust the rubber buffer stops. Tomorrow weather willing, I'm re-assembling a roof side member before pulling the other side apart.

I've removed the plugs in the bottom of my fish tanks and I'm going to poke around in there with my snakecam to see if it's drainable. Water in the fish tanks slops back into the trunk! Once, I saw an inch of water, and haven't yet discovered why so much gets in there, because for three years I've seen nada! But that was after Waxoyling everything in sight likely to have contact with water.
 
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