1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

"Soft" limp mode VS "Hard" limp mode

Discussion in 'A3/S3 Forum (8L Chassis)' started by Scullies, Apr 2, 2013.

  1. Scullies
    Offline

    Scullies Well-Known Member

    Joined:
    Feb 9, 2012
    Messages:
    1,282
    Likes Received:
    318
    [Apr 2, 2013]
    Was wondering what the differences are between the above limp modes and what triggers them.

    Awhile back I was getting an over boost fault, resulting in the boost running at 5psi. It could only be cleared by erasing fault codes.
    Is that a soft or hard limp mode?
    #1
  2. Ads

    Ads

    [Sep 19, 2014]

  3. phil miller
    Offline

    phil miller Member

    Joined:
    Sep 9, 2012
    Messages:
    845
    Likes Received:
    83
    [Apr 2, 2013]
    tbh there is only one limp mode, but say your lambda sensor is fooked yes you are in a sort of limp mode but apart from the light being on you prob wouldnt notice, yet the over boost you would notice
    #2
  4. beachbuggy
    Offline

    beachbuggy Well-Known Member

    Joined:
    Jan 27, 2010
    Messages:
    1,758
    Likes Received:
    139
    [Apr 2, 2013]
    Do you mean over boost, under boost limp mode? The Ecu has 2 pressure deviation maps that once triggered will set dtc's. there are other pressure protection maps , timing protection etc but the car needs to be pretty bad for them to trigger.
    #3
  5. badger5
    Offline

    badger5 www.badger5.co.uk Site Sponsor

    Joined:
    May 28, 2004
    Messages:
    7,331
    Likes Received:
    695
    [Apr 3, 2013]
    what map are you running on what hardware currently? Your original?
    #4
  6. Scullies
    Offline

    Scullies Well-Known Member

    Joined:
    Feb 9, 2012
    Messages:
    1,282
    Likes Received:
    318
    [Apr 3, 2013]
    I was running the remap, but I was getting very high boost spikes with the large K&N filter. I went to the guys that did the remap, but he wasn't very helpful. His answer was its impossible for the turbo to use more air than the map is asking for. :wtf:
    So I have put the stock map back on now as its getting hot, hitting 35 during the day.

    My question was more of an information question, as I have seen a few posts about "soft" limp mode and thought it was different to a "hard" limp mode.
    I was wondering if different safety measures throw you into different limp modes. As I know if the actual boost vs requested boost differs by too much - you get a "hard" limp mode, that needs to be reset with VCDS.

    Been on the nef site trying to educate myself in this ecu stuff, I was enjoying the tuning steps you were sending me for my BT setup. My wife though I was crazy tho, when I was loading files and trying to explain to her how things were changing. I might have refered to it like giving birth and watching your child grow up. :redface:
    #5
  7. Vex182
    Offline

    Vex182 Guess what I drive...

    Joined:
    Apr 23, 2012
    Messages:
    933
    Likes Received:
    59
    [Apr 3, 2013]
    I THINK "soft limp" is when the car dumps boost if possible, by using the n249 and this will not cause a fault code to be saved.
    #6
  8. badger5
    Offline

    badger5 www.badger5.co.uk Site Sponsor

    Joined:
    May 28, 2004
    Messages:
    7,331
    Likes Received:
    695
    [Apr 4, 2013]
    What hardwares on your car currently?
    #7
  9. Scullies
    Offline

    Scullies Well-Known Member

    Joined:
    Feb 9, 2012
    Messages:
    1,282
    Likes Received:
    318
    [Apr 4, 2013]
    1.8 k04, 600x300 FMIC & 3" piping, 3" downpipe (custom homebrew :sly:), Large k&n filter, forge 007p, silicone tip. stock fueling setup. Even with the stock map the boost gauge is reading 1 bar max with the k&N, when I had the stock air box and flat panel k&n filter boost was at .8 bar.
    So I assume the large filter is the cause for more air flow.
    #8
  10. JUS3IN
    Offline

    JUS3IN silver sleeper

    Joined:
    Mar 31, 2013
    Messages:
    833
    Likes Received:
    46
    [May 11, 2013]
    soft limp will reset itself but log a code. hard limp on my apy i think i got when i disconnected my injectors and cranked her over to prime the turbo i'd just changed.... never got an engine light but wouldnt boost at all until i'd reset it by disconnecting the battery.
    #9
  11. AdamNajak
    Offline

    AdamNajak New Member

    Joined:
    Mar 14, 2013
    Messages:
    9
    Likes Received:
    0
    [May 11, 2013]
    The dreaded Limp mode :/ 3 months and still havent managed to solve mine :(
    #10
  12. JUS3IN
    Offline

    JUS3IN silver sleeper

    Joined:
    Mar 31, 2013
    Messages:
    833
    Likes Received:
    46
    [May 11, 2013]
    do you have a chinese turbo? thats what was causing mine, had to have it off and send it to bill at badger 5. do you get boost creep if you bypass (link charge pipe straight to the actuator) the n75? i was still gaining boost once i done this= bad...
    #11
  13. Sam_
    Offline

    Sam_ Down under

    Joined:
    Mar 8, 2011
    Messages:
    2,829
    Likes Received:
    345
    [May 11, 2013]
    Limp mode in an S3 is like a K03s has been fitted
    #12
  14. Gops
    Offline

    Gops 6th gear @7000rpm

    Joined:
    Nov 6, 2009
    Messages:
    2,641
    Likes Received:
    286
    [May 11, 2013]
    I went into limp mode when my throttle triggered a code. It wouldn't rev or go over 5mph! Cleaned the TB and cleared codes, runs like a dream :)
    #13
  15. S3DTP.
    Offline

    S3DTP. New Member

    Joined:
    May 16, 2013
    Messages:
    9
    Likes Received:
    0
    [May 18, 2013]
    Haha Sam_ agreed, I'm limping now and would still give a few cars a decent run ;)
    #14

Share This Page