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Boot lock sensor

Discussion in 'A3/S3/Sportback (8P Chassis)' started by demi, Nov 22, 2012.

  1. demi
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    demi New Member

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    [Nov 22, 2012]
    I am having trouble with the boot lock sensor, boot is locked but on the screen coming up as open, alarm keep going off. I suspect there is a leak in rear wiper washer, is this a known fault? Left my ca unlocked today!
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  3. mike foster
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    mike foster Fossie VCDS Map User

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    [Nov 22, 2012]
    Well known fault usually caused by knackered rear wiper motor as you suspected. Washer fluid leaks into the motor and then drips down inside the boot lid lining and into the lock.

    Remove the lock and either dry it out or flood it with WD40 type stuff. Temporary fix is to remove the electrical connector and connect the two pins together making the control module think it's locked ! It won't be but the alarm won't keep going off !

    New lock may be required as permanent fix but definitely a new wiper motor. The latest version has been modified to stop this happening.
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  4. Strangely Brown
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    Strangely Brown Member

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    [Nov 22, 2012]
    I replaced the rear wiper motor on my Sportback last weekend and am waiting on a new lock mechanism to be delivered. The hardest part of the job is getting the boot trim off, fitting the wiper motor (gasket failed causing it to leak on to the lock mechanism) is dead easy as it is held in place by three bolts. The lock mechanism looks to be pretty easy as well
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  5. demi
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    demi New Member

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    [Nov 22, 2012]
    Ah so it is the leaky wiper then, I sealed it last winter! Any idea what prices are for the wiper motor or th lock?
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  6. Strangely Brown
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    Strangely Brown Member

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    [Nov 22, 2012]
    Paid £110 including delivery from Lincoln Audi on eBay. Both are brand new boxed. :)
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  7. Soot1
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    Soot1 Member

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    [Nov 22, 2012]
    The same thing happened on my Mk 4 Golf years ago, alarm going off randomly, light on dash. Yes it's water getting into the lock, don't go buying stuff until you find out where the leak is, maybe an easy cure if it's a pipe and the bootlock can be removed and dried out, although not always possible.
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  8. AidenUK
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    AidenUK Well-Known Member

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    [Nov 22, 2012]
    Nacked wiper motor, i replaced this on my A3 before it was sold. :(
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  9. Strangely Brown
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    Strangely Brown Member

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    [Nov 22, 2012]
    Ignore the quality of the photos as i only had my phone with me at the time.

    Wiper motor. You can see where the gasket between to two parts of the case had failed causing it to leak. The pipe had also worked slightly loose. I tried to repair it using liquid gasket but opted to replace it instead.
    [​IMG]

    As you can see, water had caused the connectors to corrode (the green stuff) to the point where the middle wire had snapped. The middle wire is the lock status signal which is the reason why in my case the boot light wasn't coming on.
    [​IMG]

    [​IMG]
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  10. mike foster
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    mike foster Fossie VCDS Map User

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    [Nov 22, 2012]
    Wiper motor shows as £102 and boot lock as £32 but prices have gone up recently so they maybe slightly out !

    Ring Dave at Stoke Audi and tell him you're an ASN member and he will give you a discount. However postage is on top of that so it may negate the discount !!

    Edit : just found this :-

    AUDI A3 8P 05-08 5 DOOR BOOT LOCK MECHANISM 8P4827505C | eBay
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  11. Strangely Brown
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    Strangely Brown Member

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  12. mike foster
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    mike foster Fossie VCDS Map User

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    [Nov 22, 2012]
    That price is £40 cheaper than the current ETKA price !!

    Wonder why they are selling the latest version so cheap ? At that price it's worth buying one for a spare just in case !!
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  13. Strangely Brown
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    Strangely Brown Member

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    [Nov 22, 2012]
    Still waiting on the lock mechanism but the wiper came in a sealed VAG branded box and with a two year warranty. Whats not to like :)
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  14. mike foster
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    mike foster Fossie VCDS Map User

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    [Nov 22, 2012]
    Absolutely nothing ! Think I'll get a spare boot lock as well !!! lol
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  15. MTRL
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    MTRL Split Grill!

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    [Nov 22, 2012]
    Ive got a boot locking mechanism off a 2008 3door boot lid if anybody is interested pm me.
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  16. mike foster
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    mike foster Fossie VCDS Map User

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    [Nov 22, 2012]
    Well it might fit but the part number is different between the 3 door and sportback !
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  17. demi
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    demi New Member

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    [Nov 23, 2012]
    Had some time to open it up, the mechanism inside where the jet sits has leaked, I installed an o ring last time but it has perished. the boot lock is fine, its just the 2 pin wire had some condensation on it and the copper pin has corroded slightly, took it off a good clean and wd40 on the pins and the socket and it makes good contact now.
    Opened the motor and installed a new oring and cleaned the waterways and the jets as they were slightly blocked.
    The main shaft tips where connects to the plastic housing has corroded and all water leaks from here, shame as the rest of the motor and parts dont fail appart from this.
    Last edited: Nov 23, 2012
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  18. CRC101
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    CRC101 Reassuringly Expensive

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    [Dec 23, 2012]
    demi, my car has exactly the same symptoms as the ones you opened this thread with.

    Thanks for the advice guys.

    ..........think I need to go and check my rear wiper motor.

    Just out of interest how easy is the motor to fit? I've replaced a door lock before but not gone near the wipers.

    I'm guessing fairly straightforward.
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  19. mike foster
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    mike foster Fossie VCDS Map User

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    [Dec 23, 2012]
    Motor is dead easy to change, it's held on by three bolts.

    The biggest problem is getting the wiper arm off the spindle. You may need to use a puller to free it. Like this one :-

    WINDSCREEN WIPER ARM REMOVAL TOOL | eBay

    The second biggest problem is getting the boot card off. Two torx screws behind the number plate (ish) and then some very hard pulling to release the spring clips.

    Once you've got the card and arm off it's a five minute job !
    #18

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