# My car unlocks itself

**URL:** <https://community.cartalk.com/t/my-car-unlocks-itself/45957>\
**Category:** Maintenance/Repairs\
**Tags:** doors, mazda3, mazda\
**Created:** [March 12, 2010, 3:44pm UTC](https://community.cartalk.com/t/my-car-unlocks-itself/45957 "2010-03-12T15:44:52Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![elizabethme](https://avatars.discourse-cdn.com/v4/letter/e/cab0a1/32.png) [@elizabethme](https://community.cartalk.com/u/elizabethme)\
**Post date:** [March 12, 2010, 3:44pm UTC](https://community.cartalk.com/t/my-car-unlocks-itself/45957/1 "2010-03-12T15:44:52Z")

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Help! My 2007 Mazda 3 recently started unlocking the doors as I was driving the car. If the doors were locked, they would unlock and if they were unlocked they would just keep unlocking. Annoying but manageable. I’ve recently discovered that the car is also unlocking when it’s parked so I’ve come back to a car that I KNOW I locked to find it unlocked. This clearly makes me nervous since I live in a city and would prefer that my car or its contents not be stolen by someone who notices that it’s unlocked. A new battery and 60k mile service failed to unearth any major problems. Do you have any suggestions?

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**Author:** ![missileman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/missileman/32/1366_2.png) [@missileman](https://community.cartalk.com/u/missileman)\
**Post date:** [March 12, 2010, 4:15pm UTC](https://community.cartalk.com/t/my-car-unlocks-itself/45957/2 "2010-03-12T16:15:22Z")

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To pinpoint the problem we need to be clear about your information. Do all the doors unlock or just one? If they all unlock then it’s probably the main switch that controls all the doors. I’ve seen broken switches cause this problem. A slight bump or change in atmospheric pressure or temperature can trigger the relays. If that’s not the problem then the remote door lock/unlock system may be at fault. The key fob controller or the vehicle controller may be at fault. You could try to reset the controller code and it may fix the problem. If this vehicle is still under warranty then the dealership is probably your best bet to reset the code.

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**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\
**Post date:** [March 12, 2010, 4:40pm UTC](https://community.cartalk.com/t/my-car-unlocks-itself/45957/3 "2010-03-12T16:40:44Z")

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I think that it’s much more likely to be in internal problem with the electronics module that handles the door locks. As it gets worse, it may start running your battery down.

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**Author:** ![elizabethme](https://avatars.discourse-cdn.com/v4/letter/e/cab0a1/32.png) [@elizabethme](https://community.cartalk.com/u/elizabethme)\
**Post date:** [March 12, 2010, 4:45pm UTC](https://community.cartalk.com/t/my-car-unlocks-itself/45957/4 "2010-03-12T16:45:42Z")

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It already has worn down one battery and the dealership didn’t fix the lock problem when I took it in for a new battery last week. Going back on Monday so I appreciate the suggestions.

To answer the earlier question, it is all four doors and the car is under warranty so I’ve been working with the dealership.

Thanks again!