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Convertible Top Issue – Code 02000: Switch Position- Implausible Signal

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2K views 21 replies 4 participants last post by  SwissJetPilot  
#1 ·
Greetings,

I’m hoping to get some help with an issue I’ve been having with the convertible top on my 2010 Audi TT Roadster. I’ve gone through many of the past threads on this topic — especially those with advice from SwissJetPilot, whose posts have been incredibly helpful. I’m hoping you’re still around and able to lend your expertise!

Background:

A few months back, I started having intermittent issues with the top. VCDS showed the 02000 - Switch Position: Implausible Signal code along with a fault related to the right canopy sensor. Thanks to previous posts, I disassembled the right servo, cleaned out the grease (only left it on the gear where necessary), and the top worked flawlessly afterward.

Current Issue:

After letting the car sit for about a month, I started it up and got a top error on the dash — but oddly, the top opened and closed without issue after playing with the switch.

However, after another month of sitting (as of 5/21), I tried operating the top again. This time:

  • I received a flashing top error.
  • The roof retracted all the way, but the flaps wouldn’t close.
  • The top is now stuck down with the flaps open fully, in the garage.
Diagnostics and What I've Tried:

  • On 5/21, VCDS initially showed:
    • 02000 - Switch Position: Implausible Signal
    • Left and Right Servo Sensor faults
  • Since then, I’ve cleared all the codes, and the only faults that have returned are:
    • The original right canopy sensor fault
    • The 02000 fault
  • Reset AGAIN and the only fault that now appears is the 02000 fault
  • We disassembled and cleaned the left servo unit this time (it was nasty), but the problem persists.
  • Attempted recalibration using the excellent instructions posted by SwissJetPilot — unfortunately, no movement or sound from the flaps during the process.
  • The flap alignment gap relative to the wind deflector looks within spec (~10mm), so I don’t think that’s the issue.
  • I’m wondering if the copper connector teeth inside the servo units might not be making proper contact?
Additional Observations:

  • The flaps have always moved a bit sluggishly, especially the left one lagging behind the right — which is why we chose to clean the left this time.
  • During the most recent failure, I also noticed strange behavior from the windows when using the top switch — they bobbed up and down sporadically, similar to the behavior I saw last time we worked on the servos (this seems to be totally normal).
  • We rechecked both servo units and confirmed that:
    • Grease is only on the gear/required parts.
    • Electrical contact points are clean and free of grease.
Final Thoughts:

I'm leaning toward the possibility that the flap servo motors might be failing, though I’d really like to avoid replacing them if there’s another solution.

If anyone — especially SwissJetPilot, has insight or updated troubleshooting advice, I’d greatly appreciate it. I’ll add more info here as I remember further details.

Thanks in advance to anyone who can help!
 
#2 ·
#3 ·
Thanks for your reply! I’ve attached the auto scan of Address 26 – Auto Roof as of 5/23. To add to the initial post: we tested the switch using VCDS, and the measuring blocks correctly showed when the switch was open and closed. Before reading your threads, we removed the trim to access the top switch, tested it, and cleaned it. I know it's not usually the issue, but I wanted to have it on record.
 

Attachments

#4 ·
So no other faults? In that case if the Initialization won't clear the faults it 'could' be the F171 or F202 hall sensors. There are two of them in the frame. They are just simple magnets so they're either 'on' or 'off'. They're there to let the controller know if the top is stowed or not. Unfortunately they don't have a fault code assigned to them (at least not on the Mk2 TT) When they fail the controller shuts out the center console switch and reports the 02000 DTC.

Even through they don't have their own DTC you can use VCDS to tell if they're functioning or not.

See the post linked below -



This post goes into a bit more detail on the Hall Sensors.
See Section 2.7 Defective F171 / F202 Hall Sensors

https://www.ttforum.co.uk/posts/9666673/

If it is the Hall Sensor, you can try and repair it yourself. Not an easy job but it can be done.
 
#5 ·
No other faults were present at the time of this reading, but I initially saw a canopy sensor right and left fault. I’ve attached a screenshot that I dug up of the canopy right fault. After clearing the faults a few times, the only fault that remains consistent is the 02000 fault, which is to be expected. I found the readings you mentioned, relating to the Hall Sensors. I have attached what VCDS is showing me. Thanks.
 

Attachments

#6 ·
Yep, typical fault for a RFS. For each RFS there's two possible faults; one against the motor and one against the "sensor" or potentiometer.

As described in the post I linked, here's what the data means for Group 001, Block 1; each of the five component being reported is represented by either a (1) for On or (0) for Off -

xxxx? = Convertible Top Open Position Switch (F171)
xxx?x = Convertible Top Closed Position Switch (F202)
xx?xx = Convertible Top Lock Switch Open (F294)
x?xxx = Convertible Top Lock Switch Closed (F295)
?xxxx = Convertible Top Front Lock Switch (F170) and Right (F172) - switched in series

If we look at your values for Convertible Top Status we find "0 0 1 1 1 " paying attention to the last two digits.

• The fourth digit (xxx?x) = 1 means F202 is On or Active.
• The fifth digit (xxxx?) = 1 means F171 is On or Active.

So what the Group 001 data is telling you is F202 and F171 are both On - which can not be true since the top can not be open and closed at the same time.

If the top was closed when you looked at that data, then F171 is the issue. If the top was open when you looked at that data, then F202 is the problem.

You can run the VCDS with the ignition on and manually open and close the top to see if either position changes.

Image
 
#7 ·
Thank you for your help with deciphering the top status. I think you're right on the money about the hall sensor. We did the manual top closing process, and the errors went away once the top was locked. Tried putting the top down automatically using the switch, and it went down perfectly, but the flaps did not close at all once the top was fully down. Clearly, something is wrong with the sensor that tells the computer that the top is down, which, as you identified, is the hall sensor! We will get to work on replacing it, hopefully it isn't too big of a job since we have some experience 🤞 . Thanks again for all your help!
 
#8 ·
If you do manage to replace the Hall Sensor yourself, please provide some details and photos of how you do it. That would be an immense help to anyone that runs into this problem. And with our TTs getting older, it's more an issue of 'when' than 'if' they go wrong.

This post offers some recommendations on how replace it along with some information from someone who's done it. However it's not a step-by-step guide. But we're trying to create one with the limited information we have available so anything you can add would be greatly appreciated.

Don't be shy with the camera. The more pictures the better even if you have to create multiple threads to upload all the pictures since you can only upload 10-per thread.


Image
 
#9 ·
SwissJetPilot said:
If you do manage to replace the Hall Sensor yourself, please provide some details and photos of how you do it. That would be an immense help to anyone that runs into this problem. And with our TTs getting older, it's more an issue of 'when' than 'if' they go wrong.

This post offers some recommendations on how replace it along with some information from someone who's done it. However it's not a step-by-step guide. But we're trying to create one with the limited information we have available so anything you can add would be greatly appreciated.

Don't be shy with the camera. The more pictures the better even if you have to create multiple threads to upload all the pictures since you can only upload 10-per thread.


View attachment 534225
Click to expand...
Yes, I'll be sure to grab some photos to contribute to the guide! After reading the most recent thread you linked, I noticed that OP had removed the convertible top completely. You or others mentioned that most shops do that, but I think a workaround was being discussed. Is there a definitive workaround or is it best to pull the top? Of course, I'd like to avoid pulling the top if possible. You mentioned pulling the back cover and the one around the roll bar off, and how that might make the job easier. I wasn't sure if removing the left flap and that trim would provide access to the sensor without pulling the top?
 
#10 ·
As you noticed the pictures, like the one above these are from a top that was completely removed from the vehicle. But we know a shop in the UK that does these repairs on 'regular' basis without removing the top and he has had good success. Unfortunately he's not willing to divulge proprietary information since it's part of his stock and trade. So fair play to him.

My guide is more of a theory, not an actual process, so you're heading down some uncharted and undocumented territory.
 
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#11 ·
Bonjour, ayant eu le même problème, je me greffe à la discussion.
Il faut faire 2 tests sur Vcds et regarder le "convertible top status"
Capote fermée, la fin sera 11 ou 01 ou 10 ou 00
Capote ouverte, la fin sera comme au dessus.
Le principe est que 11 ou 00 n'est pas possible puisque ça indique que les capteurs d'ouverture ET de fermeture sont tout deux ouverts ou fermés.
Ca permettra de voir quel capteur ne change pas de valeur.


Personnellement, quand j'ai identifié le capteur qui posait problème, j'ai inversé les 2 fils des capteurs dans le connecteur J256 voir si le défaut "changeait d'endroit" (et donc suivait le capteur) ou s'il restait au même endroit (defaut du J256).

Dans mon cas, le défaut à changé d'endroit donc c'est bien le capteur qui était en défaut.
Ensuite, j'ai pris un raccourci pour le changement car je ne voulais pas déposer toute la capote.... (ni aller chez un spécialiste).

 
#12 ·
Bienvenue. Veuillez noter qu'il s'agit d'un forum anglophone. Nous sommes ravis de vous compter parmi nous, mais nous vous demandons d'utiliser au moins un traducteur en ligne tel que DeepL pour vos futurs messages. Merci ! ;)

DeepL Translate: The world's most accurate translator

Welcome for the Forum!

Please be aware this is an English speaking Forum. While we are happy to have your participate, please use an online translator like DeepL for future posts. Thanks!

Hello, having had the same problem, I'm joining the discussion.
You need to run two tests on VCDS and look at the “convertible top status.”
With the top closed, the ending will be 11 or 01 or 10 or 00.
With the top open, the ending will be as above.
The principle is that 11 or 00 is not possible since it indicates that both the open AND closed sensors are open or closed.
This will allow you to see which sensor is not changing value.

Personally, when I identified the sensor that was causing the problem, I reversed the two sensor wires in the J256 connector to see if the fault “changed location” (and therefore followed the sensor) or if it remained in the same place (J256 fault).

In my case, the fault changed location, so it was indeed the sensor that was faulty.
Then I took a shortcut for the change because I didn't want to remove the entire hood... (or go to a specialist).

 
#14 ·
@ Sailordude - This post covers pretty much covers all the convertible top issues.


Based on your fault codes it's the roof flap servos -

02000 - Switch Position: Implausible Signal. This is a standard convertible top control switch lock-out. This is triggered anytime there's a fault in the Convertible Top Controller so you can't operate the top until the problem has been solved. However you can still open and close it manually. See this post (link here).​
​
03246 - Sensor for Canopy Flap; Left (G596)​
Located in the left flap servo with motor, the error occurs when the expected value is below ~42 and ~184.​
​
03247 - Sensor for Canopy Flap; Right (G597)​
Located in the right flap servo with motor, the error occurs when the expected value is below ~42 and ~184.​

Good read here -


While you can remove and clean both RFS as a DIY project be aware you will need a Ross Tech VCDS in order to clear these faults. Or you can take it into Audi Service and have them do it for you.

Image
 
#18 ·
Pump failure is unlikely without a fault code unless there's an obvious fluid leak. You can clean the RFS all day, but until you run the Output test (which also clears the faults) the top isn't going to function. Also possible to have a Hall Sensor failure which won't throw a fault code but will show up in the binary results.
 
#20 ·
#22 ·
I have both VCDS and OBDeleven (1st Gen) and each has it's own merits. I got the VCDS Hex-V2 specifically for sorting out my roof (same issues with the RFS) and then later picked up an OBDeleven Pro when they were still using credits. For quick fault scans using the App on a smart phone, the OBDeleven is quick and easy and IMHO a must have for road trips in case a dash light comes on. But for serious work you just can't beat VCDS even if you never use it's full capabilities.
 
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