Notices
 
 

  

User Tag List

Thread: Air Suspension spurious lowering 'implausible' fault code

Results 1 to 5 of 5
  1. Air Suspension spurious lowering 'implausible' fault code 
    #1
    Join Date
    Mar 2012
    Location
    Beverley, England
    Posts
    5
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    1 Post(s)
    Hi

    A few weeks ago was having trouble with air suspension whereby when left for several days it would lower onto the stops but would pump up again once engine started. I suspected a leak and booked it into local indy. However before I could get it in the air suspension failed altogether and would not pump up.

    Indy diagnosed it as failed front offside strut. This was replaced (non-OEM) and all was fine for a couple of weeks. However now the suspension has started lowering of it's own accord intermittently. It does not move when driving at speed or when parked up with engine off however when stopping to park, or reverse into drive or parking space or sometimes when first setting off etc. it lowers at the front to the point where both warning lights flash but then raises itself again to comfort and remains.

    I took it back to the indy who was unable to find any problems anywhere with the system and only fault code present was 'implausible signal'. It seems too much of a coincidence for the fault not to be related to the new strut but currently indy is saying this isn't the cause.

    My guess would be it's something to do with a position sensor on the new strut though I don't even know if they have one! Certainly seems to be something that is not directly monitored by the cars system.

    Any help appreciated.

    2005 3.0L Avant Quattro, 148000 mile.
     
    0 0 0
     

  2. Re: Air Suspension spurious lowering 'implausible' fault code 
    #2
    Join Date
    Aug 2016
    Location
    Cape Town, South Africa
    Posts
    44
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    3 Post(s)
    Hey Rods16,

    It does sound like one of the position sensors is giving a dodgy signal and the computer is reacting to this. The position sensors are separate to the struts, and there is one on each of the 4 corners. They're obvious when you take the wheel off. A little black box, with a small plastic arm, then a metal rod linking it to the lower control arm.

    I don't have any knowledge of them failing or how they fail, and I would imagine that if it was an intermittent connection then it would throw a code for an open circuit to that sensor, not just "implausible signal" (unless it says "implausible signal sensor X"??). But it's certainly possible for the inner workings of the sensor (probably some form of potentiometer) to break down and then give spurious readings to the level control computer.

    If it was me, I would connect VCDS and then log the level signals coming from the 4 corners. They are all visible in mm under measure blocks. Then when the issue happens check if there was a sudden spike or change in the reading coming from one of the sensors. I'm hypothesising that one of the sensors gives a faulty low reading, then the computer airs down to compensate, or something like that.

    Regards
    Mark
    2006 A6 Avant 3.0 TDi Quattro
     
    0 0 0
     

  3. Re: Air Suspension spurious lowering 'implausible' fault code 
    #3
    Join Date
    Mar 2012
    Location
    Beverley, England
    Posts
    5
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    1 Post(s)
    Thanks Mark, good to know where the sensors are located. I've now identified that it dumps the air from offside front when steering is put into hard lock, I'm suspecting the sensor is being contacted by the wheel causing a false reading or something. Possibly not positioned correctly when the new strut was fitted, or a fault with the strut itself when steering putting stresses on it.
     
    0 0 0
     

  4. Re: Air Suspension spurious lowering 'implausible' fault code 
    #4
    Join Date
    Aug 2016
    Location
    Cape Town, South Africa
    Posts
    44
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    3 Post(s)
    Ya, that is an interesting issue. Knowing what I know about the arrangement there, I'm going to guess that the air line is being pulled or something, like it's not routed correctly. Or alternatively the electrical connector is being stressed on the sensor.
    But thinking about it, I believe it throws "implausible signal" when it simply doesn't understand how it got to where it is. Like if you manual take all the air out of the strut without telling it to do it, like if the air line was being stressed or pulled.
    Have a good look in there with the wheel off. The problem will hopefully be obvious. The struts don't turn with the wheels turning, so I doubt it's the strut itself.
    2006 A6 Avant 3.0 TDi Quattro
     
    0 0 0
     

  5. Re: Air Suspension spurious lowering 'implausible' fault code 
    #5
    Join Date
    Jul 2013
    Location
    UK
    Posts
    1,225
    Post Thanks / Like
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    76 Post(s)
    An implausible signal is normal a broken wire/switch in a feedback wire.

    Do you have the scan to post up the full code?
    Dan
    2009/2010 2.0 TDIe SE
     
    0 0 0
     

Similar Threads

  1. Question Fault code P2563 Turbocharger Boost Control Position Sensor Circuit: Implausible Signal
    By Audikiller in forum Audi A3 - 8P - 2004 - 2012
    Replies: 1
    Last Post: 28-09-2018, 09:48 AM
  2. Replies: 0
    Last Post: 26-04-2018, 11:45 AM
  3. A3 won't start fault code 01176 - key - 008 - implausible signal - intermittent
    By dontclickonthis in forum Audi A3 - 8P - 2004 - 2012
    Replies: 2
    Last Post: 03-09-2016, 03:10 PM
  4. Q7 air suspension fault code
    By h2bnd in forum Q7 - 4L Forum - 2006 - 2015
    Replies: 0
    Last Post: 31-12-2015, 05:40 PM
  5. Spurious Alarm sounding + Suspension worn.
    By dannyboy201062 in forum Passat - B5 Forum - 1997 -2005
    Replies: 1
    Last Post: 07-02-2011, 10:35 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


 



  


Disclaimer: VW Audi Forum is an "independant enthusiast website", administered in line with guidelines supplied by VAG in the UK, and is in no way related to any of the Worldwide Volkswagen,Audi,Seat,Skoda,Bentley,Bugatti,Porsche or Lamborghini group of Companies. For official up to date information on any of there vehicles, please visit the official websites. Any comments made throughout this website, are the views of the respective poster, and in no way represent the views of the VW Audi Forum Administration, or the worldwide Volkswagen & Audi Group of companies.


VW Audi Forum do not vet and are not responsible for any information which is posted in this forum. All content is viewed and used by you at your own risk and we do not warrant the accuracy or reliability of any of the information.


Copyright: Certain "words", "phrases" and "Images" used on this website by the Administration are "Copyright" of Volkswagen GB, Volkswagen AG (Germany), Audi GB, Audi AG (Germany), Volkswagen Motorsport GB, Volkswagen Motorsport AG (Germany), Audi Motorsport AG (Germany), Volkswagen Racing GB, Bentley, Bugatti, Porsche and Lamborghini. No image can be replicated by anyone WITHOUT the relevant Companies written permission.


All trademarks and copyrights remain property of their respective owners.

No part of the VW Audi Forum website or forum may be reproduced without written permission from the site administration


PLEASE NOTE - PERSONAL ABUSE, ABUSE AGAINST THIS OR ANY OTHER WEBSITE OR ANY COMPANY WILL NOT BE TOLERATED. OFFENDERS WILL BE MODERATED OR EVEN BANNED.


This website and forum are best viewed at a minimum resolution of 1024 by 768.



  



- VW AUDI Forum - The #1 Volkswagen (VW) Group Forum - Volkswagen (VW) - Audi - Seat - Skoda - Bentley - Bugatti - Lamborghini - Porsche - Scania - MAN - Ducatti - VW Audi Forum -


- www.vwaudiforum.co.uk - www.vwaudiforum.co.uk -