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Discussion Starter · #1 · (Edited)
Hi all,

Any help appreciated! The Eos has sat for a while, we went to put them top down and it just says "system error no convert. top operation" on the center red screen and won't even attempt to put the roof down. I thought it was low battery voltage so I put the car on the trickle charger until it indicated green 100%, I cleared all codes and tried again. Same thing, won't even attempt to open the roof. I pulled codes and the roof codes are:

"3050 - No description available"

"446 Function Limitation due to Under-Voltage: Lower Limit Exceeded"

I can't find any info online about what these codes mean. I searched the fuse diagrams and none say anything about the roof or sunroof which I find odd. Any help would be greatly appreciated. The roof always worked perfectly until this.

We have the US model 3.2L VR6 engine. 2007 model year.

*Update I just tried it and it worked! I put the roof back up and tried it again and "system error no convert. top operation".

Update #2 the pump was wet and the foam around the pump saturated with water. I dried everything out and it works perfectly again! Water and electronics DO NOT MIX. Can attest to it.
 

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First, make sure the engine is running when operating the roof. You didn’t mention this in your post.
If that doesn’t work, you’ll have to check that all the sensors on the roof are reporting correctly. Here’s a guide for how to do that.
 

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If you do nothing to the roof controls then start the car and get voltage or battery errors, you have to get that problem sorted first.

You should have turned on the key without starting, scan and clear any fault codes, then key on and rescan without starting. If the battery is good I wouldn't expect to see any voltage related errors. If there are, then there is more to look at and it doesn't sound like you are using a V.W compatible diagnostic tool to help you? When you have done that, any roof, door or other electronic module faults shown with compatible diagnostics may be caused by trying to operate the roof with a faulty battery. In future, only operate the roof after starting the car when the engine is running.
 

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Discussion Starter · #5 · (Edited)
This is a posh way of saying the battery (and/or alternator) is knackered.
Thanks for the replies all. Haha. Our German cars seem to always speak to us so politely! I did not know the engine should be running to operate the roof, good to know. My hunch was battery as well but the engine starts just fine so it threw me off the trail. Batteries make sense since it just sat for 2 weeks before this. They each also have a dead cell from 2 years ago also. I also posted in the EOS Facebook group and someone said it takes more power to operate the roof than to start the engine, which I also would never have guessed!
 

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Discussion Starter · #6 ·
I took the batteries to the local auto parts chain for free charging with their industrial Optima charger. They brought these batteries back from the dead 2 years ago so we'll see what happens but I'm not optimistic this time. I remember last time the batteries are $500 plus shipping if I install myself, 5 times more $$ than a regular 12v!

To rule out the very simple, is there a fuse for the roof, sunroof? I don't see one in my diagrams for any of the 3 fuse boxes, which seems very odd.

I did a bunch of reading on this forum and found this 00446 - Ross-Tech Wiki
and the link suggests checking fuses first.
 

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I did not know the engine should be running to operate the roof, good to know.
In theory it doesn't need to be, but in practice its always good practice to have the engine running in case the battery struggles, because it is quite a big load. The roof can still operate with a bit of an undervoltage though, so I think your batteries have a dead cell (but just guessing - but its easy to test them with the right tools anyway).
 

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someone said it takes more power to operate the roof than to start the engine, which I also would never have guessed!
Wrong information I'm afraid. But electronic modules start giving out and do bad things when the battery voltage drops below 9 Volt. The roof and sunroof share the same 50A fuse in the engine bay fuse box. There aren't many so you can test all of them. But if that fuse is dead, you probably have a serious electrical fault with the roof pump, roof controller or the sunroof motor.

Any battery that has suffered abuse (e.g left to go flat!) and is 'brought back to life' is always going to be risky. Batteries are relatively cheap compared to the damage that can be done to car electronics and time spent fault finding if you keep using a bad battery.

Battery voltage is nominally 12.6V and an old battery could drop to <10V when loaded. When the engine is running the alternator should hold the battery at around 14V and when loaded with the roof pump, the alternator should still keep holding that voltage even on idle and the roof will open and close a little faster. When a poor battery is allowed to drop to <10 volts on load, the roof pump motor, sunroof motor, window motors, the starter relay and starter motor all run slower and take more current. Replacing the battery ensures the starter relay won't burn out, but running the engine will reduce power to the other motors and they should last longer.
 

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Discussion Starter · #9 ·
You guys have been a wealth of information, thank you. I checked the fuses and they're all fine. Batteries are still charging at Auto Zone.

We love the EOS but have 2 toddlers now, both in huge rear facing car seats. Once the younger one went into a toddler car seat too the EOS became impossible to use. No way to get them in. We bought my wife a crossover, and can't afford to keep the EOS but we haven't been able to sell it. All these issues have developed while trying to sell it!! o_Oo_O

The first potential buyer came and while looking at it the DVD navigation suddenly won't recognize the DVD or eject it!! So they wouldn't buy the car. Next potential buyer was serious but while he was looking at it the roof refused to work. That's of course when I posted this.

By the way, do you guys know any solution to the DVD issue? It says wrong DVD even though it's clearly the right one and has worked for years....I just cannot believe all these issues came up literally while serious buyers were looking at the car for sale. The worst luck!
 

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DVD/CD players in cars can have a hard time and the tracking laser/IR heads can get misaligned with vibration. You can try a DVD cleaning disc first? Depending on what price you are looking to sell for, you could replace the dvd unit with an Android head unit? They will see a modern looking screen display, won't look at anything else on the car and buy it straight away! :)

After they charge the batteries get them to do a voltage and load test. I still think you are taking chances not wanting to replace them before selling the car?
 

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Discussion Starter · #11 ·
We replaced the batteries and the roof still doesn't work roughly 50% of the time. I don't understand it. I scanned for codes and there are no roof codes at all. I thought maybe the new optima batteries (which came in boxes) had sat on a warehouse shelf for a while and might not be at full voltage so I left them on the trickle charger all evening and overnight. The trickle charger indicates 100% and same thing. Probably half the time it'll say the error.
 

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From his first post it didn't look like the OP was using V.W EOS roof compatible diagnostics, it certainly isn't vcds ? If his diagnostics doesn't show roof sensors, then it's unlikely to show faults and he's working in the dark until this is confirmed.

If the roof can be opened to the side flaps open position and be propped when it works, a simple check of diagnostics capability is to disconnect one flap sensor plug at the bottom of the 'fish tank', ignition off/on and rescan. If a flap sensor fault code isn't given, the diagnostics is pretty useless for EOS roof fault finding.
 

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Discussion Starter · #14 ·
It's showing roof code 3050 again. The voltage one is stored. It has some voltage related steering column codes too, although that works great. This is with BlueDriver, which is a scan tool that can read engine, airbag, ABS, sound system, body module codes. I think the scanner sees code 3050 but doesn't know what the description is for Volkswagen. Probably since it's a convertible only code and a Volkswagen only code at that.

Ok with no codes.......what stage of roof operation doesn't work?
It works perfectly half the time. The other half it won't even begin the operation to put the roof down. It'll just say "system error no convert. top operation" on the red screen in the center gauges, flash up the roof symbol with the arrows and do nothing. When it goes down it'll always come back up without any issue.
 

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932 (the window motor code), I would think, needs sorting out first.
446 (low voltage) - if its not the battery then it needs more detail investigation, ie checking of powers and grounds to the roof module. Now, this is where a skilled technician would approach it differently to a DIYer. They would aim to find the situation which generates the intermittent code, then disturb as little as possible while doing further tests. This means, not touching or wiggling wiring harnesses, no unplugging, etc. Then backprobing (with the right size needles) the relevant connections and testing with a suitable load.

It might be really obvious - green crusty stuff all over the place. Or it might be a 'pin fitment issue'. Or a weird, tiny break inside a wire.
 

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ETA I can't be sure what you mean about stored codes etc. Its worth recording the codes, then clearing them, then seeing what returns, if you have previously had battery issues but have now replaced those.
 

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Discussion Starter · #18 ·
ETA I can't be sure what you mean about stored codes etc. Its worth recording the codes, then clearing them, then seeing what returns, if you have previously had battery issues but have now replaced those.
I did clear the codes once I saw the same ones there after the roof wouldn't work a few times after replacing the battery. Also with the batteries disconnected for a day theoretically that would've cleared them as well.

Good thought about the window code. I'll try the relearn procedure with that window. The one I'm also a bit concerned about is the

470 ACTIVE/STORED Combination comfort Databus in Single Wire: Open Circuit

Wondering if it's saying there's a short circut in the vehicle wiring somewhere. Water getting in or a bare wire grounding to the body somewhere.
 

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Discussion Starter · #19 ·
Now THIS is the sort of thing I had been looking for. I spent some time searching the forum using keywords like the error message, roof and those codes and never found this. Pinouts is exactly the sort of thing I'd hoped to find here as I have a E38 BMW 740iL and that forum has a pinout directions for diagnosing everything lol.

I see the first thing you mention is water damage. Because of not driving during the pandemic and buying a crossover for my wife to driver the children around in, the EOS has sat outside for well over a year, maybe even 2 without having any seal treatments applied. The cabin has water ingress, to the point that the inside of all the windows would be covered in dew in the mornings over the winter. Although never any water on the seats or floor mat and I've never noticed any water or moisture in the trunk. There is also some standing water in the left basin where the left roof column gets stowed. I'll work on getting that standing water out asap and I think the moisture in the cabin is mostly gone. There isn't any dew on the inside of the windows anymore. Thank you both for your continued help and especially voxmagna for taking the time to help other EOS owners by writing your guide.
 

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Pinouts are not for many who think you can plug in diagnostics that tells you exactly what's faulty. When a roof control module is wet and intermittent with no communication, wiring and interconnections in the trunk can get wet or damaged by humidity so there is huge potential for intermittent faults. Diagnostics only reports roof faults when the roof control module is working.

What starts as pleasurable top down EOS ownership can become a lifelong uncertainty of not knowing when or where the roof operation may stop next. I had one intermittent fault and needed a second means of confirming a roof sensor error. The problem was in the wiring loom, not a faulty sensor as reported by diagnostics.
 
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