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Non start a4 1.6

Discussion in 'A4/S4 forum(B5 Chassis)' started by chrisa4quat, Oct 27, 2011.

  1. chrisa4quat
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    chrisa4quat Member

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    Car won't start. Immobiliser light flashes. Starts and cuts straight out. Checked and it's both keys that fault happens. Read fault codes. Key signal lost from ecu. Key signal and engine start blocked by immob. Checked wiring. Thinking its gonna be white box or reader coil. Cos of age of car don't really wanna spend any money but too good a car to waste! Any ideas? Or help?
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  2. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    Its probably the coil.
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  3. chrisa4quat
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    chrisa4quat Member

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    I think it's had one at some point as 2 new keys or ignition all other keys fit locks. Don't know when etc tho
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  4. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    sounds like it, but then its presumably been a used one as the dealer would have supplied the barrel with the proper key, so maybe its just died as well...
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  5. chrisa4quat
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    chrisa4quat Member

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    Ouch 101quid plus vat for new barrel and coil less my discount. 88 plus vat. Can get used one or owt?
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  6. bez101
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    bez101 Yorkshire & Humber Rep. Regional Rep

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    when my old b5 did this it was the wire that connect the coil round the igg switch
    15 quid i paid
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  7. chrisa4quat
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    chrisa4quat Member

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    What ya pay for etc bez? Where from?
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  8. bez101
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    bez101 Yorkshire & Humber Rep. Regional Rep

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    from audi
    dont no part number
    just tell them its from igg coil iv been told its very comon on the b5
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  9. NineNails
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    NineNails Proud sponsor of the snack food industry

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    I've fixed this issue on a couple of cars in different ways...
    First off is the white box (immo) Did you ever try unplugging the immobiliser box's plug & plugging it back in again?
    The contactors on the two halves of the plug are made from different metals, which react together in the presence of oxygen - a galvanic cell.
    I fixed mine by unplugging and plugging in several times, then spraying with electrical contact spray to prevent corrosion. Was totally reliable for 4 years after that.

    Now the reader coil. Just so you know, the reader coil is not coded to anything. As far as I understand, they are purely used to energise the key's transponder through induction, and the transponder then transmits to the immobiliser box, the immo box then "talks" to the ECU.
    I found the problem was in the IDC connector that connects to the reader coil around the barrel. IDC = insulation displacement connector - this is when the crimp contact connects to the wire by cutting through the wire insulation. I.E. it's a mechanical connection, not soldered. The wire to this connector was very taught which had caused a bad connection at the crimp. As it was constantly being pulled. I soldered each crimp to each wire (2 in total) to make a good connection. Also pulled some of the immobiliser wire back through towards the coil and cable tied this to the barrel to try and stop it becoming tight again. Think this happens over years of steering wheel adjustment.
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  10. chrisa4quat
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    chrisa4quat Member

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    Now I'm totally confused as to what It could be. I'll have to have a look further
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  11. bez101
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    bez101 Yorkshire & Humber Rep. Regional Rep

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    its gona be that wire
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  12. NineNails
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    NineNails Proud sponsor of the snack food industry

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    What are you confused about Chris? Is there something I can try to explain in a better way for you at all? You've really gotta investigate further before you start throwing parts at it coz 9 times out of ten it's usually just down to faulty connections/wiring
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  13. chrisa4quat
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    chrisa4quat Member

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    The wire bit. I haven't managed to get bottom steering wheel cover off yet. Think need to remove air bag and steering wheel. Checked wiring from reader coil to immo box (white) unplugged and plugged back in still same. I'm not used to these old cars. Immobiliser systems in cars I am familiar with are ignition, ecu and dash - newer cars
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  14. NineNails
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    NineNails Proud sponsor of the snack food industry

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    Yeah you will need to get that bottom cover off. You would need to do that anyway if you wanted to swap out that reader coil. Here's a removal guide to help you get that cover off >>> AudiWorld Tech Articles
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  15. chrisa4quat
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    chrisa4quat Member

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    Need to get a pic from etka or summat I reckon.
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