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Automatic start/stop: system fault! Function unavailable

jimmydougle Apr 1, 2015

  1. jimmydougle

    jimmydougle Active Member Audi S5

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    Hi all,

    I've had yet another fault with my S3 this week, I think I'm on 8 now. I've had this one before and they fixed it (well might not have done now I have it again).

    I turned my engine on. There was immediately a loud grinding noise coming from the engine for about 2 seconds, then this error came up on the screen: "Automatic start/stop: system fault! Function unavailable."

    However, the system does sometimes work again when I turn the engine off and on again. Has anyone else had this problem? Last time I had this the dealer told me that the crank shaft sensor was broken and the car automatically shuts down other "non-essential" features of the car.
     
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  3. veeeight

    veeeight I am a very pretty girl VCDS Map User Black Edition

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    I've had the variable cam shaft mechanism fail on my S3 at 5000 miles ish, which inhibited Pre Sense and ACC from working.

    Good quality, these Audi cars ;)
     
    Snibo likes this.
  4. jimmydougle

    jimmydougle Active Member Audi S5

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    Ah now I have that as well, perhaps it's related.

    I have a list for my dealership to look at when I take it in, I'm guessing they don't like me anymore after the email I sent... The "quality" was a subject I raised.
     
  5. Gorillajebus

    Gorillajebus Member

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    Registered myself just to tell you that I had the exact same issue.

    Started my S3 in the morning and heard that grinding nose as well and the message on the screen displayed me the exact same message.
    Had my dealer check it but they said this error would not be recorded in the bordcomputer which makes it hard to diagnose.
    The only thing they found was an undervoltage in the on-board power supply a couple of times.
    Still they couldn't tell me whether that was the reason for the start/stop failure.
     
  6. jimmydougle

    jimmydougle Active Member Audi S5

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    Welcome to the forum :)

    Thanks for letting me know, this is very useful. It's strange that the computer doesn't pick this up. Did they do anything to fix the undervoltage? I'm guessing you still occasionally get this fault come up if they couldn't fix it.

    I wonder if Audi can be convinced to replace the start/stop device. Does anyone know if that's a possible thing to do?
     
    Gorillajebus likes this.
  7. Gorillajebus

    Gorillajebus Member

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    The only thing the dealer did was checking the battery which was healthy and fully charged.
    They said they don't know what to do about it and asked me to gather more information for them if possible.

    At first I thought it might be affected by the ambient temperature, but it wasn't.
    From what I observed over time the failure occurred randomly.

    I own the S3 for around 1 1/2 years now and this start/stop failure happened maybe 5 to 6 times.

    Last time the error occurred was last week.
     
  8. kikin

    kikin Active Member

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    It happens to me when:
    - not driving my car for more than 2 days and it takes a little miles to get it operative again
    - when driving too much time and engine is too hot.
    Not sure is it a problem or just related to ambient temperature or engine.
     
  9. HawkeyeS3

    HawkeyeS3 Well-Known Member TeamMisano Audi RSQ3 quattro Audi A1

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  10. HawkeyeS3

    HawkeyeS3 Well-Known Member TeamMisano Audi RSQ3 quattro Audi A1

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    So if you read the updates to my thread, it looks like I have a fuelling issue (no idea why, but its seriously overfuelling at tickover for some obscure reason). That aside the turbo sliders are rattling as well (apparently) so it's down at the dealers now awaiting analysis.

    What they did tell me though was that any issue with the engine though will "activate" start/stop. The "get around it to get home" is to de-activate start/stop manually by turning on the switch on the dash (it's the only way we could get mine to the dealers this morning), but what it does tell me is that start/stop can mask the issue (they use it to stop the engine being damaged, which is fair enough I guess - just depends (as in my case) where it chooses to do it! The fast lane of the M25 in rush hour traffic was not the time nor the place!

    So it looks like my issue was a bit different from yours possibly, however the other thing I did learn was that odd bits of software do get upgraded. The Audi Assist guy this morning wondered whether the software for controlling my upper injectors / fuel rail was updated during my last service and has caused the issue. We await the synopsis (which won't be until next Tuesday earliest)
     
  11. Jimowl

    Jimowl Member

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    sorry to resurrect. I had my S3 saloon delivered yesterday - 230 mile at delivery (Brighton to Sheffield - hmmm....). Drove it 40 miles into Nottingham. Today on driving back to Sheffield through Nottingham I came to a set of lights. Stop/Start turned the engine off as it had been doing. Then it abruptly restarted and I got 'Automatic Stop/Start: system fault! Function unavailable'. I switched off the ignition then back on but no change. At the next lights I switched off, removed the key then switched back on and it was reactivated.

    Do I need to be worried? 2 days old and <350 miles!!
     
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  13. veeeight

    veeeight I am a very pretty girl VCDS Map User Black Edition

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    Yes.

    ACC unavailable can be a symptom of something else not working correctly.

    Get it scanned for faults.

    Or it may be just a glitch.
     
  14. SJR88

    SJR88 Active Member

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    I've had this error message come up. The car has been fine today, had fairly light use, then suddenly after parking up and switching the engine back on, it seems like the engine fan is fairly loud. No grinding sound, just the fan. It goes off when you switch the engine off and comes back on, displaying the error message each time. It's an A3 1.4 TFSI. Done 11,000 miles.

    Any ideas? Don't really fancy booking it in again, it goes in every couple of months for something!
    image.jpeg
     
  15. Andyescos

    Andyescos Well-Known Member Team Panther Team Sepang Audi S3 Audi RS3

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    Snap, had the same message a few weeks ago, Told Audi, they didn't seem too concerned, it's not done it since.
    image.jpeg
     
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  16. SJR88

    SJR88 Active Member

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    Did you get any engine noise at the same time?
     
  17. Andyescos

    Andyescos Well-Known Member Team Panther Team Sepang Audi S3 Audi RS3

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    Didn't hear anything, the car's going in on Saturday to fix another issue, I was going to get them to see if it logged the issue and what caused it.
     
  18. SJR88

    SJR88 Active Member

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    Ah right. Thanks for the advice. I'll probably book it in soon anyway, there's a rattle that's been annoying me when going over bumps! Had so many issues with this car.
     
  19. Andyescos

    Andyescos Well-Known Member Team Panther Team Sepang Audi S3 Audi RS3

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    join the club, this is my second as the first was rejected, this with has also had a lot of issues, sadly Audi don't seem to care.
     
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  20. kikin

    kikin Active Member

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    Just recognize weeks ago that this message appears always in comfort mode with my DTUK FSR on. When i remove it this week for service the S/S works always fine. Thinking if thereĀ“s an error with low battery or something like that produced by the tuning box.
     
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  21. SJR88

    SJR88 Active Member

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    I know, they tend to just say they can't find a fault or say it's a "characteristic", sort of make you feel like you're making it up! Good luck anyway.
     
  22. Bittern

    Bittern Well-Known Member TDi Audi A3 S-line owners group

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    Found this on a TT forum with peeps having the same issue

    QUOTE: as you know I also had this problem so took into Audi Poole on Monday this week. After having the car for two days Audi told me that after discussing the fault with Audi in Germany (didn't say who), it was decided that the fault lay with the Stop/Start button itself. The button was replaced and the car was delivered home on Wednesday evening. I have driven it for the last two days and fingers crossed, the problem seems to have been resolved. UN-QUOTE

    Might be worth checking this out ?
     
    Last edited: Jan 21, 2016
  23. Andyescos

    Andyescos Well-Known Member Team Panther Team Sepang Audi S3 Audi RS3

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    Well it seems the fault was due to the charcoal filters, not sure where they're located but they need replacing.
     
  24. CybrHwk

    CybrHwk Member Team Sepang Audi S3 quattro

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    My Start/Stop isn't working at the moment either, but I think that's more down to the lower temperature than anything else. Haven't seen any errors on the dash or a grinding noise. It just has the A crossed out when i'm sitting at lights etc, like i've switched it off
     
  25. Aman_Aus

    Aman_Aus New Member

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    Hi All, New to this forum and even new to Audi experience.. Just bought this A3 1.4 TFSI (2013) yesterday and realized that the auto start stop function is not working. Called the dealer (toyota in this case as i bought it from them) and its booked for diagnostic on 1st May.. I am not sure how much they can do as its not their model. Can anyone suggest some checks i can do myself before 1st May. ALso, the car was with dealer for 2-3 months for sale so it hasn't been driven much as i read it in this forum that sometime this could also be the cause. no strange noise from engine as mentioned above as potential cause. Temp inside/outside is also not much different.


    Also, the attached pic is taken when the car is still and just started. is it normal for the RPM gauge to be where it is i.e. 0.8? I believe some tunning might be required.. again apologies I am not fully into the automobile so parden my ignorance.


    Thanks
     

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  26. steverobertsbbc

    steverobertsbbc Active Member

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    Maybe your battery voltage is low if it has been sitting in a dealer for a while. Give it a good run around and see if it's better after a restart.
     

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