Welcome to the VW AUDI Forum - VWAF.

Results 1 to 7 of 7
  1. #1
    Join Date
    Apr 2008
    Location
    Lancashire
    Posts
    20
    Post Thanks / Like
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Question Limp mode - what is it?

    Hi Guys,

    Today my 51-plated Audi A3 TDI had a sudden loss of power whilst in 4th gear on the motorway.

    I have done some research on here and it turns out it probably went into limp mode (i.e. I couldn't get above 3,000 revs no matter what).

    However, what I would like to know is what is 'limp mode' and what causes it? Can anyone answer me this?

    My theory is that my car went into 'limp mode' as I was very low on fuel at the time (I'm someone who always waits until the reserve light comes on before re-fuelling). If this low fuel level is what is the likely cause of the 'limp mode' then I will without a doubt change my attitude to fuel levels!

    Thanks in advance!

  2. #2
    Join Date
    Aug 2007
    Location
    Wirral, Merseyside
    Posts
    2,429
    Post Thanks / Like
    Thanks
    69
    Thanked 39 Times in 32 Posts

    Re: Limp mode - what is it?

    I wouldn't have thought that low fuel would have put the car into limp mode. You're best getting the car read for fault codes which should give you a better idea.

  3. #3
    Join Date
    Sep 2006
    Location
    Tyldesley, Manchester, UK
    Posts
    5,934
    Post Thanks / Like
    Thanks
    214
    Thanked 100 Times in 92 Posts

    Re: Limp mode - what is it?

    I am with Hagis. I have had my low level petrol light on more than once in my Passat and never encountered any problems.
    No Germans, Only Italian.

  4. #4
    Join Date
    Apr 2008
    Location
    Lancashire
    Posts
    20
    Post Thanks / Like
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Limp mode - what is it?

    Well I have to say I have had the fuel light come on and never had this problem. I can't begin to wonder what causes it.

    Can anyone help?

    Cheers.

  5. #5
    Join Date
    Feb 2008
    Location
    Crosby, Liverpool
    Posts
    505
    Post Thanks / Like
    Thanks
    1
    Thanked 10 Times in 10 Posts

    Re: Limp mode - what is it?

    Its probly low fuel. Its happened to me 3 times now becasue Im a scruge! Ill drive for about a week after the fuel light comes on. It will go into limp mode about 5 miles before it runs out. Its so hard to drive, It happened to me yesterday whilst waiting to turn right on a busy main road witha HUUUGE sainsburys HGV behind me.When I pulled away and couldnt go over 5mph he wasnt a very happy bunny! A good old stop and restart sorted it untill the petrol station.

    However RE your origional question, the car will go into limp mode if it reaches any kind of critical state were it 'thinks' anythign other than light driving will harm the engine.It sets a rev limiter on the engine so it can only be driven slowley, Iv found that the fow fuel limit is about half of the regular error limit. Normal lim pmode is around 3000 RPM but my A4 with no petrol will only do about 1500/2000 RPM. In the case of low fuel, It helps preserve that last little bit and also give you a last REAL reminder that it really will run out of fuel! Other limp mode reasons are things like low oil lever/pressure, high temp, low water level, brake system faults or any critical engine/saftey system error. PLus for thsoe who arent in the know, theyre more likely to take the car to a garage to get it checked out if its in limp mode,as they wont have a clu whats going on with it, and the more serious fault (should) get diagnose and maybe even cured!

    So ther you have it, limp mode ....DONE!

    Audi A4 B5 1.6 -1998 <~~~ GONE
    Audi A4 B7 2.0 - 2005<~~~ GONE
    Audi A4 B5 1.8 T 1996 <~~~Here for now


  6. #6
    Join Date
    Apr 2008
    Location
    Lancashire
    Posts
    20
    Post Thanks / Like
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: Limp mode - what is it?

    Thanks for the advice/help!

    After it happened I went to the petrol station and put some fuel in, together with a full can of Redex - not had the problem since (touch wood!).

    Cheers!

  7. #7
    Join Date
    Apr 2007
    Location
    Lancashire
    Posts
    1,450
    Post Thanks / Like
    Thanks
    0
    Thanked 40 Times in 35 Posts

    Re: Limp mode - what is it?

    Limp mode is a generic 'reduced power' mode, that results from any number of potential engine problems. (resulting in reduced fueling & N75 operation)

    On a TDI 'limp mode' is usually the result of real time boost pressures being out of spec for a given period of time. i.e Overboosting or underboosting.

    Low fueling resulting in reduced combustion & charge pressure can cause underboost limp mode directly before running out on a VE engine.

    I would not have thought the PD engine would suffer from this, as the injector pressures are very high.

 

 

Similar Threads

  1. Limp Mode
    By bbb in forum Passat - B5 Forum - 1997 -2005
    Replies: 10
    Last Post: 25-03-2010, 11:45 PM
  2. Limp mode - think I'm going to cry!! lol
    By MikeMc in forum Golf MK4 - 1999 - 2004
    Replies: 18
    Last Post: 22-04-2009, 09:47 AM
  3. Limp Mode
    By shuggy2005 in forum Passat - B5 Forum - 1997 -2005
    Replies: 8
    Last Post: 22-10-2008, 08:35 PM
  4. Is this limp mode??
    By fasttdi in forum Audi A4 - B6 Forum - 2002 - 2005
    Replies: 1
    Last Post: 03-02-2008, 03:37 AM
  5. Limp Mode...
    By milenia in forum Passat - B5 Forum - 1997 -2005
    Replies: 3
    Last Post: 26-10-2007, 03:57 PM

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
  •  
Back to top






Disclaimer: VW Audi Forum is an "independant enthusiast website", and is in no way related to any of the Worldwide Volkswagen,Audi,Seat,Skoda,Bentley,Bugatti,or Lamborghini group of Companies. For official upto 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: 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, and Lamborghini. No image can be replicated by anyone WITHOUT the relevent Companies written permission.


VW Audi Forum is an AUTHORISED retailer for the Surf City Garage range of car care products


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.





Page copy protected against web site content infringement by Copyscape


- VW AUDI Forum - The No1 VW Audi Forum - Volkswagen (VW) - Audi - Seat - Skoda - Bentley - Bugatti - Lamborghini - Porsche - VW Audi Forum -


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