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

A4 immobiliser problem

Deanh Oct 21, 2012

  1. Deanh

    Deanh New Member

    Been having problems with my immobiliser,

    battery died a few months ago and as it was dying the immobiliser would kick in after 2 seconds of starting which I put down to the weak battery,

    put a new battery on but had the same problem since, meaning to start the car I have to disconnect the battery for 20 seconds and as soon as I switch it off I have to do the same thing again to restart it,

    Its been to the garage twice and put on vag com and 50/504a and on vag com it says the key signal is too weak, the instrument panel is clear of faults, and on the 50/50 software says the ecu is in static mode and won't talk to the immobiliser!!!!

    anyone any ideas?

    i have tried a more powerful battery but that still has the problem so I know it's not a battery fault and my key has no battery in it
  2. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    I think the battery is a red herring.

    The normal immo activation is to shut the engine down after a second or two, so what you describe there isnt anything battery related.

    Have you tried another key?

    Might need a new reader coil, or sometimes the wiring to the coil causes issues.
  3. hades-

    hades- Well-Known Member VCDS Map User

    as above iv sorted quite a few B5's with immob problems
    changed the wire from reader and all was good
    easy ish job to do and parts not a lot of £££.
  4. jcb

    jcb Active Member

    where is the reader and how do you remove/replace/repair the wiring?
  5. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

    Its part of the ignition barrel.

    Not sure if you can swap the reader on its own, or if you need to buy a whole new barrel though.

    The wiring on earlier cars can prove problematic though!

Share This Page