Mazda 6 Car Alarm keeps going off! Help! :)

bobert50

bobert50

bobert50

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Hi guys,

I've been trying to get to the bottom of my car alarm problems for the past month and any help would be very appreciated. Here is roughly what has happened so far....

In Early May, the car alarm on my 2010 Mazda 6 started going off throughout the day. My immediate thought was batteries... I changed both of the batteries in my key fobs and then waited to see if this fixed the problem.

The next day, still the alarm is going off... I 'm starting to see a bit of a pattern with hot weather/sunshine but that was just a theory. I decided that since i knew the car battery was very old that this should be the next thing to replace, so I picked one up and did that myself, gave it a good run-around so the ECU-re-learnt everything and then left it parked at my house again. Basically, during the coronavirus, my car really isn't getting much use! There also seems to be a possibly related issue where my boot occasionally seems to be unlock itself and opening slightly (not fully up). This has happened about 5 times in this same period that the alarm is going off and never happened before this.

Anyway, it stayed quiet for a day or two and then off the alarm goes again! I was on the verge of taking the car to a proper garage to see if they could find any info on perhaps a dodgy sensor, and then a few weeks ago... the sun vanished, and the alarm didn't go off for weeks at all. I'm certain that the alarm stopping seemed to completely 100% coincide, to the day, with a drop in temperature, and was worried when the temps increased again lately, but the alarm continued to stay off... until last night!

My neighbour rang my bell this morning to say that my alarm was going nuts at 5am this morning :( I somehow didn't actually hear it myself but I'm sure he'll be telling the truth. He said it went of three or four times all close together and stopped within about 5 seconds, which is totally in-keeping with the previous behaviour. It hasn't gone off since but it does seem inevitable that it will.

If i had to guess... i have serious suspicions that, with the timing of this recent one happening, and the fact i happened to use the car the previous day (for the first time in weeks), and i did open up the boot, and the fact that there is possibly a related issue with the actual boot, it possibly could be the boot sensor?

Has anybody got any ideas what I could try before taking it to a garage on Monday? I'm not even sure what the sensors look like or if i could wipe along them myself, or whatever else is an option to me. I feel pretty guilty / bad for my neighbours right now and really would like this sorting asap! preferably without costing myself an absolute fortune.

Any thoughts are extremely welcome! :)
 
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Every so often the alarm on my Mondeo will start randomly going off. Opening and closing the doors, tailgate and bonnet a few times always seems to fix it.
 
Meaker said:
Is it following a pattern with the rain we have had? Maybe a leak?
Click to expand...

Hmm, it doesn't seem to. It seems more likely warmer temps/blazing sunshine that triggers an increase of the alarm going off. I've tried to see if it is damp anywhere and everywhere seems completely dry. I feel 75% sure that going into the boot of the car recently for my tyre pump is what probably led to it going off again during the night last night, since it hadn't gone off for two or three weeks and it had rained a lot in this period.
 
have you left/got anything electronic in the car? phone, tablet, etc?

I know it sounds dumb, but I used to have a Mazda 6 MPS, which I know is a little older than this, but they're renowned for the alarm to go off randomly if there's a phone or tablet left in the car, even if it's in the glovebox or tucked away in the seat pockets.
 
DereksDontRun said:
have you left/got anything electronic in the car? phone, tablet, etc?

I know it sounds dumb, but I used to have a Mazda 6 MPS, which I know is a little older than this, but they're renowned for the alarm to go off randomly if there's a phone or tablet left in the car, even if it's in the glovebox or tucked away in the seat pockets.
Click to expand...

Thanks for the reply. Unfortunately absolutely nothing is in the car :(
 
IAmATeaf said:
Said that he has.

Take a look at all the door, bonnet and boot sensors and check if you can to see if they look clean etc.
Click to expand...

Thanks for the help. This'll sound a really stupid question, but i can see for example the boot locking mechanism but I'm not even sure what part / where the sensors are! A bit embarrassing! :) I did use some wd40 on the lock earlier today to see if that helps on the major locks.

Right now, I'm just REALLY hoping it doesn't go off at 5am again and disturb the neighbours.
 
bobert50 said:
Hi guys,

I've been trying to get to the bottom of my car alarm problems for the past month and any help would be very appreciated. Here is roughly what has happened so far....

In Early May, the car alarm on my 2010 Mazda 6 started going off throughout the day. My immediate thought was batteries... I changed both of the batteries in my key fobs and then waited to see if this fixed the problem.

The next day, still the alarm is going off... I 'm starting to see a bit of a pattern with hot weather/sunshine but that was just a theory. I decided that since i knew the car battery was very old that this should be the next thing to replace, so I picked one up and did that myself, gave it a good run-around so the ECU-re-learnt everything and then left it parked at my house again. Basically, during the coronavirus, my car really isn't getting much use! There also seems to be a possibly related issue where my boot occasionally seems to be unlock itself and opening slightly (not fully up). This has happened about 5 times in this same period that the alarm is going off and never happened before this.

Anyway, it stayed quiet for a day or two and then off the alarm goes again! I was on the verge of taking the car to a proper garage to see if they could find any info on perhaps a dodgy sensor, and then a few weeks ago... the sun vanished, and the alarm didn't go off for weeks at all. I'm certain that the alarm stopping seemed to completely 100% coincide, to the day, with a drop in temperature, and was worried when the temps increased again lately, but the alarm continued to stay off... until last night!

My neighbour rang my bell this morning to say that my alarm was going nuts at 5am this morning :( I somehow didn't actually hear it myself but I'm sure he'll be telling the truth. He said it went of three or four times all close together and stopped within about 5 seconds, which is totally in-keeping with the previous behaviour. It hasn't gone off since but it does seem inevitable that it will.

If i had to guess... i have serious suspicions that, with the timing of this recent one happening, and the fact i happened to use the car the previous day (for the first time in weeks), and i did open up the boot, and the fact that there is possibly a related issue with the actual boot, it possibly could be the boot sensor?

Has anybody got any ideas what I could try before taking it to a garage on Monday? I'm not even sure what the sensors look like or if i could wipe along them myself, or whatever else is an option to me. I feel pretty guilty / bad for my neighbours right now and really would like this sorting asap! preferably without costing myself an absolute fortune.

Any thoughts are extremely welcome! :)
Click to expand...
I've got a 2008 Mazda 6, and it has a tendency to do funny things if it doesn't detect all the doors and boot are shut properly (even though they are).
I make sure I regularly lubricate all door locks and hinges so the doors shut easily.
To ensure my tailgate is shut properly, I open one of the doors so the air pressure doesn't build up and this means i can give the tailgate a good slam down.
I also make sure I close my doors with a good slam as well.
It sounds brutal but it seems to work.
 
Paul_RD said:
I've got a 2008 Mazda 6, and it has a tendency to do funny things if it doesn't detect all the doors and boot are shut properly (even though they are).
I make sure I regularly lubricate all door locks and hinges so the doors shut easily.
To ensure my tailgate is shut properly, I open one of the doors so the air pressure doesn't build up and this means i can give the tailgate a good slam down.
I also make sure I close my doors with a good slam as well.
It sounds brutal but it seems to work.
Click to expand...

Thank you! I'm going to do exactly this during the afteroon. No alarm of late and long may that continue!
 
bobert50 said:
Thank you! I'm going to do exactly this during the afteroon. No alarm of late and long may that continue!
Click to expand...
Out of interest, I make sure I keep my battery fully charged every 2 to 3 weeks using a CTEK battery charger as I am not using the car at the moment due to being on furlough.
A few weeks ago, I left it about 3 weeks and just after the period of extra hot weather (for the UK), I noticed that the boot wouldn't pull itself in that extra little bit with the electric boot closer - I then went to start the car and the battery turned out to be low enough that the starter wouldn't crank.
After charging, I did a proper test on the battery using a "Powertest 5" battery tester (does a high current drop-test) and the battery checks out as good.
Was it because I left it 3 weeks? or was it linked to the hot weather? - I don't know! - I'm making sure I charge it at least every 2 weeks at the moment though.

I have got the workshop manual and electrical diagrams (on .pdf) to refer to if you want a copy?

Incidentally, I've had this vehicle for three years now and I think that it may have caused problems for the previous owner as the alarm sounder doesn't sound - but the hazard lights flash.
I haven't bothered to see if the sounder has been disconnected as my neighbours have reported to me that sometimes they see my hazard lights flashing - I think it's best to leave it alone for now!
 
I used to have a 2008 Mazda 6 which did the same thing. I narrowed it down to being one of the sensors which detect that the door is open. To get round this I used to lock it using the key in the door as that disabled the alarm.
 
Thanks Silent Bob, that reminds me - when you lock it bobert50, press the button on the remote twice, if the hazards flash once, then flash three times after a few seconds, the vehicle is happy.
If you don't get the three flashes, something is wrong - open and slam shut all the doors (including the bonnet and tailgate) and try again (or use the key).
 
Paul_RD said:
Thanks Silent Bob, that reminds me - when you lock it bobert50, press the button on the remote twice, if the hazards flash once, then flash three times after a few seconds, the vehicle is happy.
If you don't get the three flashes, something is wrong - open and slam shut all the doors (including the bonnet and tailgate) and try again (or use the key).
Click to expand...

Hi, I'm really sorry for the late reply! Thank you very much everyone for the thoughts and replies.

This thing about the three flashes I will try in the morning 100%. I'll be very very curious!
 
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