My VW Alarm Goes off by Itself….. Reasons why its happening

November 13, 2012
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On some Volkswagen models it is not uncommon to have sporadic alarm issues. Often time’s people believe that they have a problem with their keys, remotes or some other part that is associated with their alarm system. Commonly they are under the impression they cause the alarm to go off by itself. The alarm on your VW going off by itself is not likely to be related to the keys or remotes.

 

This alarm concern is most commonly a result of a failing door latch. The door latches on VW models have a micro switch inside of them that tells the vehicle if the door is open or closed. Overtime the micro switch starts to break down, and rarely completely fails right away. The reason why the door latch failures causes the random alarm problem is due to the micro switch. When the micro switch on the door latch assembly begins to fail it will send the improper signal to the vehicle, causing the vehicle to believe the door has been opened.

 

For example you have a 2001 VW Jetta, your car is parked in your driveway with the alarm armed. All of a sudden your alarm starts going off for no reason. Nothing hit your car and no one had attempted to break into it. The most likely culprit is your door latch assembly.
Why did this happen?
Most commonly what has happened it your car is sitting with the alarm armed. All the doors are shut.If you have a random failure of this micro switch, it tells your vehicle that the door is now open. Which will set the alarm off as your vehicle thinks that someone has opened the door without disarming the alarm.

 

The next question becomes “How do I know which door latch is bad?” Your car has more than one door after all. On most current model Volkswagens there is a switch near the from dome light that selects when the interior lights come on. Make sure this switch is on the setting so the interior lights will turn on when the doors in the vehicle are opened. Once you do this all you have to do is open each door on the vehicle a few times to see which door will not turn the lights on.Keep in mind most time the failure is random and will become more frequent overtime.

 

Once you determine which door does not turn on the interior lights you now have identified the door latch assembly that has gone bad. Most commonly it is the driver side front door latch, as this is the most frequently used door.

 

Here we have a video installing an OEM VW Drivers Front Door latch on a 2001 MK4 Jetta 

 

 

Which latch do I need for my Volkswagen?

 

Jetta MK4 Door Lock Actuators 1999.5 – 2000 – 2001 – 2002 – 2003 – 2004 – 2005.5

Drivers Side Front Door Latch Assembly 3B1-837-015-AS

Passenger Side Front Door Latch Assembly 3B1-837-016-CF

Drivers Side Rear Door Latch Assembly 3B4-839-015-AM

Passenger Side Rear Door Latch Assembly 3B4-839-016-AM

 

Jetta MK5 Door Lock Actuators 2005.5 – 2006 – 2007 – 2008 – 2009 – 2010

Drivers Side Front Door Latch Assembly 3B1-837-015-AT

Passenger Side Front Door Latch Assembly 3B1-837-016-CG

Drivers Side Rear Door Latch Assembly 3B4-839-015-AP

Passenger Side Rear Door Latch Assembly 3B4-839-016-AP

 

Passat B5 Door Lock Actuators 2000 – 2001 – 2002 – 2003 – 2004 – 2005

Drivers Side Front Door Latch Assembly 3B1-837-015-AS

Passenger Side Front Door Latch Assembly 3B1-837-016-CF

Drivers Side Rear Door Latch Assembly 3B4-839-015-AM

Passenger Side Rear Door Latch Assembly 3B4-839-016-AM

 

Golf, GTI MK4 Door Lock Actuators 1999.5 – 2000 – 2001 – 2002 – 2003 – 2004 – 2005.5

Drivers Side Front Door Latch Assembly 3B1-837-015-AS

Passenger Side Front Door Latch Assembly 3B1-837-016-CF

Drivers Side Rear Door Latch Assembly 3B4-839-015-AM

Passenger Side Rear Door Latch Assembly 3B4-839-016-AM

 

GTI, Rabbit Door Lock Actuators MK5 2006 – 2007 – 2008 – 2009

Drivers Side Front Door Latch Assembly 3B1-837-015-AT

Passenger Side Front Door Latch Assembly 3B1-837-016-CG

Drivers Side Rear Door Latch Assembly 3B4-839-015-AP

Passenger Side Rear Door Latch Assembly 3B4-839-016-AP

 

Beetle Door Lock Actuators 1999 – 2000 – 2001 – 2002 – 2003 – 2004 – 2005 – 2006 – 2007 – 2008 – 2009 – 2010

Drivers Side Front Door Latch Assembly 3B1-837-015-AS

Passenger Side Front Door Latch Assembly 3B1-837-016-CF

 

Beetle Convertible Door Lock Actuators 2003 – 2004 – 2005 – 2006 – 2007 – 2008 – 2009 – 2010

Drivers Side Front Door Latch Assembly 3B1-837-015-AT

Passenger Side Front Door Latch Assembly 3B1-837-016-CG

 

Please note that this article is the opinion of an individual, and is not a diagnostic of your vehicle. This based on a professionals experience.

Spacing and dashes may be added to the part numbers depending on how you search you may find different results. Other variations include for front latches 3B1837015AS, 3B1 837 015 AS, 3B1837015AT, 3B1 837 015 AT, 3B1837016CF, 3B1 837 016 CF, 3B1 837 016 CF and for rear latches 3B4839015AM, 3B4 839 015 AM, 3B4839016AM, 3B4 839 016 AM, 3B4839015AP, 3B4 839 015 AP, 3B4839016AP, 3B4 839 016 AP

Paul Barrett

About

CEO | Ex Dealer Technician | VW Audi Parts Savant | Father | Husband | Chipotle Enthusiast
Creating a VW and Audi Parts Company that Cares

27 Comments

on My VW Alarm Goes off by Itself….. Reasons why its happening.
  1. Will
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    I had this issue with my 2007 mk5. The dealership wanted over $500 to fix it. Never did get it fixed, just couldn’t lock my car ever.

  2. Aaron
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    Most well informed video online, hands down. I’ve searched the net for this issue and knew I found the right guy immediately. It’s very obvious this guy knows his business. Huge kudos out you, well done.

  3. Jorge Santiago
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    Hey! I’m having this problem in my jetta 2001, the other problem is that the car doesn’t show what door is, because the inside lights turn on with every door, so I don’t know what door latch is having the problem.

  4. |

    HI Paul
    this appears to be the problem I am having with my 2001 VW Cabrio. I believe it is the drivers side front door latch that is failing. can you refer me to the correct part number I would need to find to replace and fix the alarm problem?
    thank you
    Bill

    • Paul Barrett
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      Im sorry but the latch from your car has been discontinued and is no longer available.

      • Bill
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        Thanks that is a bummer. Is their another VW model where the part is compatible? Ie GTI or Passat for instance?
        Thanks

  5. mattbell
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    Hey. I have 2003 golf. I went out to my car after it sat for a few days and battery was dead. I charged it up and when I turned it off I noticed my locks were still going up and down even with the key out. My alarm would go off sometimes too. So I figured my latches were draining my battery. Took car the car to my mechanic and he had it for four days but locks or alarms never acted it up. He ran tests on it today and said the only thing he’s sees wrong is I need a new battery. Is this normal? Thanks for any advice

    • Paul Barrett
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      Sorry based on that info its tough to say. If the battery is dead then you will have to get a good one in there before you can figure out whats up.

  6. shannon buenning
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    I HAVE 2000 JETTA bought car 2 yrs ago lr window and door lock not working and gas door not working checked gas latch it is good then lost drivers window function and then the rest of windows the door lock is the only function that works on the driver door switch nothing else have replaced both door latches on driver and lr doors checked the wires harness for broken wires cant find anything out of the ordinary the key in the outside of the door will work the windows up and down but not the lr it does nothing was told this model does not have a body control module but looks to be one just below the steering wheel to the left when i got the switches in this box started ti click every 4 or 5 seconds cars runs and drives fine no other problems please help do not have much hair left!!!!!!

    • Paul Barrett
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      Shannon it could be the window motor or could be related to the convenience module. This will need to be properly diagnosed to track down whats going on.

  7. Joanne Light
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    Hi Paul,

    Yes, coming to this website was the best thing that has happened. If I just don’t lock my car, will the security system stop going off random;y? I figure, as Will mentioned above, that the dealership will charge me hundreds of dollars as their labour rate is $110.00/hour.

    Joanne

    • Paul Barrett
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      Yes if you dont arm the alarm its wont go off randomly but I really dont advise leaving your doors unlocked.

  8. Cherie scott
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    I have a 2000 VW Jetta i never lock.my car nor use the alarm. Lately it’s been going off when you open the door or start the car. Also the Windows won’t roll down but the motor does make the noice that its tying.. help

    • Paul Barrett
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      Probably 2 different issues. Most likely you have a door lock/ latch issue mentioned above as well as a window regulator problem.

  9. Russell
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    Just wondering if you have any input on my situation. I swapped door skins on my mkv since they were dinged up. Before I finished buttoning everything up, I checked to make sure the doors would open and close, however, once I locked the car, the one won’t open at all from inside or out.

    • Paul Barrett
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      Start by checking fuses but based on what your describing it could be something that wasn’t done properly or just a coincidence that the door latch went bad at that time.

  10. Connie
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    My husband has a 1987 VW Jetta. When I started it the other day the alarm went off and we haven’t figured out how to disable it. The car won’t start with the alarm going off. Help what can I do?

  11. jean beaulieu
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    hi. i read a lot but not find my problem.. when i start my beetle 2001 the alarm start for 30 seconds but the car start…very strange and disturbing for neighbors!!

  12. John capes
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    2011 Touareg alarm goes off after locking when walking away with fault for alarm horn no signal in comfort module horn beeps nice place under wiper trans and nice price

  13. Michelle
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    I have a 2000 beetle. ..today I opened with the key fob and the alarm went off and could not stop the alarm. .my husband was going to disconnect the battery .but the alarm stopped can not use the fob to open the door or close it through the remote. .but can unlock it with entering the key. ..I have replaced the battery in the fob but still no good. . Also now can not open the windows please advice

    • Paul Barrett
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      You should read the article above it explains your issue.

  14. Heather
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    I just purchased a 2011 vw toureag hybrid and dealer says they had it since July , I just purchased it yesterday . Hard to believe it never went off in 2-3 mos they had it . but its gone off 4x’s in 2 days.

    HMMM hoping Porsche Dealership I went to fixes it . c MON

  15. Brian
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    Hi, my 01 Jetta Wagens drivers side key will unlock/lock/alarm/disalarm when it is cool outside but when its hot it does not. My indy said it was the drivers side latch as you showed in the above video. The dealer said it could be the hood latch or a bad wire. Basically, it works when it is cool. Your thoughts are appreciated. Brian

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